Click no start- [and other no start] tips.

Eric Experience

Well-known member
To solve the “Click no start” problem we need to divide into groups of problems.


The first group could be the Battery and Charging System.
The second group could be Security and Relays.
The third group could be the Starter and its Solenoid.


Initial Testing
To find out which group you have, test by turning on the interior light , turn the key if the light goes out it is the first group Battery and Charging system.

If the light stays on, next test by running a wire from the small terminal on the starter.
To do this you should make up a test lead. Get a 2m or 8 feet length of hook-up wire. Connect a small alligator clip to each end. Connect one clip to the small terminal on the starter and the other end to a multimeter lead. The other meter lead must go to earth (ground/negative). The seat mounting bolts are a good earth.

With the meter resting on the seat and switched to 20 volts DC, turn the key. If the meter reads 12 volts you have good security (SKREEM) and relays circuit so go to the third group. If you do not get the 12 volts the problem is in the second group, Security and Relays.

Background information.

Most electrical problems are caused by poor electrical connections. To understand why we need some basic science.

All metals except gold oxidize when exposed to moisture. Oxides are good insulators. MB uses good quality connectors with rubber seals but a little bit of moisture still gets in. The more important pins are silver plated. If a plug has provision for 6 wires but only has 5 fitted then there should be a rubber plug in the 6th hole to keep moisture out. Mixing metals for connections makes things worse. Cheap pins are tin pated steel, better ones are tin plated brass, the next up is plated silver. The best are gold plated.

If something is not working there is a good chance it is not properly connected to the loom. If you have a bad connection the ECU cannot see the device and chucks a code. If you then scan the vehicle you will get a message like XYZ is faulty when in fact it is not, but is just not connected.

Things like relays are hard to keep free of moisture so they are placed under seats or in closed boxes.

High current circuits have an added problem. A small amount of oxide causes some resistance this resistance causes the connection to get hot which greatly accelerates oxidation. This is very noticeable on battery terminals. When a heavy cable with a copper crimp is bolted to steel, because you have mixed metals you get oxide problems.

This is common when a negative battery cable is earthed. All is not lost if you keep moisture out with some form of moisture barrier like lanolin or silicone. If the oxidization occurs inside a crimp you can remove the oxide with something like soldering flux, the function of fluxes is to get in under oxide layers. If you clean a crimp with flux you must then wash and dry it quickly then soft solder it. Washing your engine with water is a sure way of generating many faults. Using a steam cleaner on any modern engine can lead to a very big repair job.

Battery and Charging System
If you have a problem in the first group you must decide if the battery is flat or there is a cable problem.

To test the battery connect a multimeter directly to the battery terminals it will normally show 12.6 volts. Get someone to turn the key. If the battery voltage drops to say 9 volts then your battery is not charged. If the voltage stays up around 12 then you have a cable problem.

To find the cable problem place one meter lead on the negative terminal and the other lead on a shiny metal part of the engine, turn the key again, if the meter reads less than 1 volt your battery earth is OK if it reads say 4 volts then your earth cable is the problem.

If your battery earth is good then test the positive terminal connection. To do this place one lead on the positive terminal directly and the other lead on the copper lug of the heavy wire. With key on, once again if it reads less than 1 volt you are Ok if it reads more your positive terminal is corroded.

By now you know if it’s the battery or the cables. If the battery is flat then we have to decide if it’s a faulty battery or a charging problem.

A common problem with Sprinters is the cable that connects the alternator to the battery. To test this it is best to get the engine running, so best to charge up the battery with a good 3 stage charger. If you only have an old style battery charger then it is prudent to disconnect the earth terminal on the battery to charge it by connecting directly to the terminals.

Once you have it charged and reconnected, start the engine. To decide if it is charging the battery use your multimeter to measure the battery voltage, it should be above 12.6 and slowly rising. A bit of fast idling should bring the voltage up to over 13volts. If this voltage is not rising over 12.6 [or less] then you may have a potential cable problem.

To test this connect your multimeter to the large terminal on the alternator. While the engine is running, with the voltmeter negative lead earthed your meter may show the same voltage as the battery. If it does you have an alternator problem. If the voltage at the large connection of the alternator is more like 14 volts then you have a cable problem.

If you have a cable problem then remove the earth lead on the battery first (for safety), then remove the cable. When you have the cable out, look for discolouration of the wire going into the crimps. If you find that, repair as in the discussion of corrosion above. Note there can be a heavy fuse in the cable under the engine, this is unlikely to be blown but it could be corroded.

At this stage we should consider the glow plugs. If when you turn the key the glow plugs come on it tells us that the ECU is happy for the engine to start but the start relay is not being energized. If we keep trying to find the fault turning the key many times then we risk flattening the battery because the glow plugs draw a lot of power. We are also shortening the life of the glow plugs by constantly heating them. If you have this situation it is best to unplug the glow plug controller, if you can find the glow plug fuse then pull it. If you are not able to find the fuse you can unplug the small 4 pin plug that connects the controller to the ECU.

Security and Relays
If the problem is in the second group then we have to work through the cct [aka circuit] to find the cause.

The starting circuit is complex for safety and security. The way it works is to first establish if you have a valid key. that verified, it checks to see if the transmission is in neutral, then the ECU checks if the basic parameters of the engine are safe to start. If all that is OK then the start relay is energized.

If you can find your start relay using the excellent information that is posted on this forum then you can feel the relay to find out if it is being energized.
Fuse Block #2 Fuse Map 2004
https://sprinter-source.com/forum/showthread.php?t=24683

If it’s not or you are not sure, pull the relay out and look at the pins, if they are clean and shiny then we have to look at the voltages on the pins in the relay socket. Pin 30 should have 12 volts, pin 87 is the lead to the starter and will show 0 volts. The other pins 85 and 86 will have voltage across them when the ECU is trying to start. To verify this place your meter leads in 85and 86 turn the key. If you get nothing then the ECU is not telling the relay to start. If you get volts when the key is turned then the relay is being energized but is not sending the voltage to the starter, this could be a faulty relay or the wire to the starter is open.

Starter and its Solenoid

If the starter is faulty we need to pull it out and test it. Never ever short out the big terminals it is dangerous and proves nothing. The other thing to never ever do is hit the starter with a hammer. This practice started in the days of crude stator wiring, The modern starter has a permanent magnet stator that is made from very strong rare earth magnets these magnets are reliable but brittle. Eric.
 
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CJPJ

2008 3500 170 EXTD 3.0 V6 OM642.993 4.182
Important useful information; deserves to be a Sticky:
Thanks Eric
 

coolestmanalive

New member
Thanks for posting this. Its really super important to have insight on such a maddening issue.


That being said, I argue that the first step should not be simple diagnosis.

It should be replacing the battery with a nice solid AGM.


Obviously once you have a chance you should diagnose, and you should begin the diagnosis with the simplest and most basic diagnosis that you can.


However, this gremlin has a tendency to strand people. Whether you depend on your van for your livelihood or you are on vacation with your family or you are just at the supermarket, your first goal is typically to get the vehicle moving, rather than to begin the process of diagnosis.


I would say that before anything, you should try the battery.


it will give you invaluable diagnostic information and it may very well solve your pertinent problem.
 

220629

Well-known member
Some other posts/threads which may be helpful for No Start.

What may work as a T1N temporary work around. It is not a repair.

Note that the lamp check dash lights displayed will give an indication of whether the fix will work for you.

mehr4x4 Eric No Start/No Crank Temporary Solution
https://sprinter-source.com/forum/showthread.php?t=42157

Some raw data/links. It is a mix of T1N and NCV3, but the basics apply to both. I *plan* to get back and edit the info a bit to dress things up.

Ah... an NCV3... there have been many reports of failure of the "Y cable" that connects the starter, alternator and battery together.
(there's even a fusible link in the alternator segment).

There are many things that can prevent starter cranking... dead solenoid, dead starter contacts in the ignition switch, and (in the NCV3) sick logic/relays in-between.

*do the following with the key OFF and out of the ignition*
You can test the solenoid (and Y-cable) by locating the starter and (carefully, with the tip of a big screwdriver and being VERY careful to avoid hitting any other metal on the Sprinter) bridging the gap between the two heavy wires on the solenoid (the little cylinder thing on the side of the starter... where the wires attach).
That should make the starter spin (but perhaps not engage).
Now jump from the battery feed wire to the *smallest* wire on the solenoid (avoiding the thicker goes-into-starter wire).
That should cause the solenoid to pull in, and the starter to engage with the flywheel and start cranking the engine.
(beware: this is a diesel.. if there's anyresidual fuel or oil in the cylinders it may fire a chuff or two)

OK... if the first crank (thick wire to thick wire) works but the 2nd didn't, it's the solenoid at fault.
If they both worked, then the ignition key's twist isn't getting electricity down to the solenoid. Look upstream.
If neither worked, and the 2nd (little wire) didn't make the solenoid go CLUNK, then suspect the Y cable.(or engine-to-battery ground connections)
If the solenoid went CLUNK but the starter didn't spin, it's the starter.

Basic Starter Diagnostics 101...
--dick

Voltage drop test all the battery and ground wires and connections......you would be looking for excessive voltage drop that would indicate the area with high resistance (poor connection, poor slice, corroded pinch eyelet or wire. Look for "green" copper at the splices and end under the insulation.

autostaretx drew out a perfect troubleshooting plan.......adding hit lightly tap the starter body with a hammer.....old school back yard test, just moves the parts enough to temporarily fix a poor connection in the solenoid or brushes (similar to hitting a bump:hmmm::hmmm:)
Battery Low Voltage Hard Start Low Charge

This is not a Cheap Trick as such, but may save multiple trips to the shop and unnecessary repairs if you have low charging or voltage problems.

There are some cables and connections which seem prone to problems. The large in-line fuse connection seems to be a common theme.

I've noted that there MAY even be a commonality of operations such as simply changing out a battery which disturbs the cables/connections and causes a poor connection to get worse. I have no data.

There is a no start thread here.
No crank no start compilation
https://sprinter-source.com/forum/showthread.php?p=569638


Read this first. Thanks goes to Dennis Linden Engineering. :thumbup::thumbup:

Guys
This cable is my opinion a source of lots of threshold voltage problems and DPF/DEF issues.
Least that's from where I am sitting in my shop office!

I have seen no fewer than 5 Sprinters this month (years 2007 to 2011) ALL with alternator charge issues that in every case was traced back to that cable and the in line fusible link.

The cable as posted previously is cheaper from the Mopar system list is $86. Its the same even for the MB 2011 model version. MB parts system wants $250ish for the same part.

This is not to be taken lightly, a new 200 Amp alternator is about $600 retail and if you have a twin A/C set up there is about 4.5 hours of labor to R'n R it, so its worth taking some care about "watts go'n on"! (or Amp 'n Volts in this case).:rolleyes:

Now threshold voltages are important because I have seen alot of vehicles roll through the shop with DPF and DEF issues all with limp or reduced power modes. Get the voltage up to at least 13.98v and codes will clear and stay out, with a reduction to 12.95 and the supply through a defective cable won't balance the consumption.

The "penny drop for me" didn't drop until yesterday when I cleared out multiple codes on a 2010 model with cable/charging issues. Lurking as a soft code was cat regeneration!
Blasted voltage problems!

Equally I have a lady owner up in the mountains that keeps threatening to bring in her 2008 model in with DPF issues. I asked her if she had changed her alternator recently--The answer came back yes by a local shop!
I am sure if I get to look at that cable it will be burnt and the insulation melted off!

Check yours because if it degenerates sufficently you might get a short down and your alternator will be sweating bullets !
A cable like that will have lot of smoke built into it--Don't let the smoke out! :rolleyes:
More on this later.
Dennis
20150408 edit:
A recent thread with some tips for changing the cable.
https://sprinter-source.com/forum/showthread.php?t=39104

More details here:

https://sprinter-source.com/forum/showthread.php?t=10155

This is from the NCV3 section, but may have commonality with all NAFTA models.

20101212 edit:
Some recent threads about cable problems.

Here is a DIY solder repair method which seems to have good success.
https://sprinter-source.com/forum/showthread.php?p=127315#post127315

Weird charging problem
https://sprinter-source.com/forum/showthread.php?t=13791

Battery/charging/starter cables
https://sprinter-source.com/forum/showthread.php?t=13606

2011/03/07 edit:

Another recent post that traced to a bad cable. The symptoms vary a bit on these problems. Thanks goes to michaeljeffery for the picture and all posters for the info.

Battery not holding charge.
https://sprinter-source.com/forum/showthread.php?t=13833

20110623 edti:

There's been a few recent threads which may be helpful.

no-start condition after many warnings
https://sprinter-source.com/forum/showthread.php?t=16511

Intermittent starting problem
https://sprinter-source.com/forum/showthread.php?t=6490

Another jump starting caution.
Batt/Alt cable fuse
https://sprinter-source.com/forum/showpost.php?p=141306&postcount=30
(Thanks goes to Plummer.)

As with all single posts the original thread can be accessed by using the link in the upper right corner.

Thanks goes to all contributors to the above threads.

vic

Edit: Some NCV3 Alternator Information

This thread is actually in the For Sale section, but VanFan and others did some research so there is good general application information in the thread. :thumbup:

https://sprinter-source.com/forum/showthread.php?t=25372

Added:
Unfortunately the post was deleted. It gave details on NCV3 alternator replacement. Basically it said that the NCV3 alternator cannot easily be upgraded to a higher amperage unit as the T1N can. Replace an NCV3 alternator with same rating unit.

Thanks goes to VanFan and all contributors. vic

A recent comment with some additional detail. Thanks goes to John.

Check the battery/alternator cable at the starter. The cable comes from the alternator and goes to the starter. At the starter, the cable splits and goes to the engine start battery and another cable runs up to the quick jump start assembly at the air filter assembly. Where the cable splits, we have seen internal (hidden) corrosion at that connection. Corrosion at that connection will lower the voltage and amperage to the starter and act like a bad starter solenoid. This is another version of the corrosion and voltage drop we see in the fuse link of the alternator cable. Hope this helps.

Thank you, John
Sprinter Store
http://sprinterstore.com/
A division of Upscale Automotive, Inc.
19460 SW 89th Ave.
Tualatin, OR 97062
503-692-0846
Advice on No Start Testing

Some very good advice from Autostarex Dick and Showkey for starter testing. Be very careful when when working around batteries and jumping the heavy terminals. Remove rings and metal jewelry. If metal gets across the battery supply source serious burns can result.

The original thread is here. Not just for NCV3 models.

Sprinter not starting....
https://sprinter-source.com/forum/showthread.php?p=248095


The NCV3 starter solenoid is available through Summit Racing. 50 bucks as of 2006/12/23.

You can also remove the starter and bench test it, it should take less than 30 minutes to remove the starter (it is not hard, easier removal than many other vehicles).
I bought my new solenoid from summit this year www.summitracing.com/parts/bch-2339305066 it worked great.
 

mgmtoo

Member
Just to add something to this! My 2004 TIN had a no start, and it was the ignition switch!
All dash lights worked, turn the key and nothing! Switch was worn out.
 

220629

Well-known member
Some links to T1N documentation.

.
.
[... I would have expected the Start Relay coil to be grounded under the driver’s seat?]

Nope. The relay is triggered to ground by the ECM aka ECU. The ECM has some common ground points.

Some info is here.
https://sprinter-source.com/forum/showthread.php?p=293545

https://sprinter-source.com/forum/showthread.php?t=31208

https://sprinter-source.com/forum/showthread.php?p=400071

vic

Your guess is as good as mine. It was used as a tire truck before, so there is a lift gate on it, bunch of extra lights, a massive air compressor in the back etc.

So I checked the starter relay circuit as per the manual

How I understand it: <snip>
Basically none the pins are giving me the values they should ...
I'm sorry to say it, but that's not even close... :frown:

My first project upon buying my van was troubleshooting a failed starter motor - it was a pretty steep learning curve, made worse by the van being parked on the street an hour away. In the Canadian Rockies.
In January. :bash:.
But I've become VERY familiar with the sequence of events as you turn the ignition key.
Allow me to walk you through the Starting System so you'll have a better idea of what to test and when to test it, and some of the points of failure that can crop up. Okay, here we go...

Here's the Starting System wiring schematic from the 2006 shop manual:
https://sprinter-source.com/forum/attachment.php?attachmentid=94592&d=1519702015

First look at the bottom of the schematic and know that when the Ignition Switch is in Position #2 (Run) the Engine Control Module will, among other things, energize Pin 30 of connector C3 (labelled "Starter Motor Relay 12 Volt Supply"). This feeds +12 volts around to splice S108, which feeds Pin 86 (coil +) of the Starter Motor Relay, as well as Pin 86 (coil +) of the Fuel Pump Relay.

Following up the right side, you can see that the ECM also provides the Fuel Pump Relay's Pin 85 (coil -) with a (switched) path to ground via Pin 55 of connector C2 ("Fuel Pump Relay Control"), which it does, so the relay closes, and the low pressure fuel pump in the tank is powered on. BUT... because the ECM has not yet grounded the "Starter Motor Relay Control" at Pin 58 of connector C2 (at bottom middle), Pin 85 (coil -) of the Starter Motor Relay is still isolated and the relay remains in its normal open position, connecting pins 87A (load open) and 30 (load common).

In this state, with the key in Position #2 (Run), the fuel pump should be running. The Starter Motor Relay should show +12v at Pin 86, and +12v at Pin 85. If there is no voltage at Pin 85 the relay coil is bad and you should replace the relay. Pin 87 should be isolated. Pins 30 and 87A will both have continuity to ground via the starter motor solenoid winding, otherwise check the connections on the BK/YL wire and the starter solenoid coil.
(when I say "should show", I mean you should measure +12v between that point and the chassis ground.)

Okay. Up at the top left corner the drawing shows Fuse Block #1, and if we consult page 8W-10-13 we will learn that the VT coloured wire coming out on Pin 3 of Connector C3 carries the +12v output of the Ignition Switch's #3 (Start) position.

So, when you turn the key to "Start", the violet wire at C3-3 gets +12v and this energizes splice S219, Pin 87 (load closed) of the Starter Motor Relay, and Pin C2-36 at the Engine Control Module ("Ignition Switch Output - START").

The Engine Control Module sees the 'Start' voltage signal on Pin C2-36 and does some internal checks. If authorized, the ECM connects Pin C2-58 ("Starter Motor Relay Control") to ground. This provides a ground for Pin 85 (coil -) of the Starter Motor Relay, the relay closes, and the +12v power from the ignition switch flows from Pin 87 through to Pin 30.

The BK/YL #12 wire connects (via cavity 2 on plug connector C101) to a #14 BK/YL wire, which connects to the Starter Motor solenoid. There it energizes the pull-in and hold-in coils of the solenoid, which draw in a plunger that engages the motor pinion into the flywheel's ring gear then closes a switch to connect the motor windings ("M") to the starter BATTERY(+) via a BK #1 cable, and the motor cranks the engine. :cheers:

In this state, with the key in the Position #3 (Start), and current flowing to the Starter Motor Solenoid, you should see "some" voltage at both Pin 87 and at Pin 30 of the Starter Motor Relay. If you see NO voltage at Pin 87 check the ignition switch or look for a short to ground between the relay and starter motor. If the starter motor solenoid hasn't drawn in with a 'clunk' and you see the FULL battery voltage at Pin 30, then check the BK/YL wire and the starter solenoid coil for breaks. If there is voltage at the starter solenoid, check first the engine ground strap then the starter motor. If you feel/hear the Starter Motor Relay 'click' and see voltage at Pin 87 but not at Pin 30, then replace your relay.

When you release the key to the #2 (Run) position, this disconnects splice S219, so the Starter Motor's "pull-in" coil releases, the solenoid plunger springs back, and the motor is disconnected from the starter Battery(+). The ECM detects the loss of 'Start' signal on C2-36, and disconnects C2-58 from its ground, causing the Starter Motor Relay coil to release and return to its normal open position.
---------

I hope this puts your previous checks in a better context?

1. Check that pin 30 has ~12V at all times, compare to a B+ pin (I understand this be any hot wire, I used the red wire in the bottom of the steering column fuse box) I got 0 volts at pin 30 where the relay plugs in

Pin 30 (load common) connects to the starter motor solenoid, so has continuity to ground at all times. So zero volts is normal unless you are cranking.

2. Check continuity between pin 87 and a fused b+ I got no contuity
Pin 87 is connected to B+ only when the key is twisted to the "Start" position.

3. pin 85 should have voltage if the key is in the ON position I think I had 3.5V on this
Pin 85 (coil -) should show full voltage in ON, though it may be getting pulled down a bit by the drain through the Fuel Pump Relay winding? Pull the Fuel Pump Relay out, then check it again.

4. Pin 86 should show ground all the time.
This is just wrong. Pin 86 (coil +) should show full voltage when the key is on.

Since the starter relay draws its power from the starter motor and then the battery, I guess the next step is too see if the starter is getting voltage and ground.
Do check the battery connections and the ground strap next to the driver's side engine mount, but the Starter Motor Relay does NOT draw power from the starter motor.

Access (to the starter motor connections) is brutal. Any advice?
Study it from above, but approach it from below and behind. I'm skinny enough to lie feet-forward with my belly under the front axle, and from there I can reach forward over the cross member and get a wrench on the starter connections. You can also lie sideways with your body under the bell housing. You'll want a mirror, otherwise just go by feel - there are only three connectors.

Good luck, and keep us posted on how you make out.

-dave
 
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mhobson

New member
I am having this problem with my 2002 w902, lhd french registered, but turn key no click and warning lights except for glow plug, oli pressure and handbrake turn off. There is no current going to the starter trigger so I think it is a sevurity system fault. I have looked at your fuse block locations but mine seem to be different to your diagrams, the one under the steering wheel and under the side of the drivers seat but do not hold any relevant fuses or relays. The strip of relays under the front of the drivers seat are arranged very differently. In the past if for some reason the motor stalled it would have the same symptoms but after one or two more tries it would start again as normal, I thought that there may be a system to stop using the starter when the engine is running but do not know if this is the case and if so where would I locate the system, thanks, Michael
 

4wheeldog

2018 144" Tall Revel
I am having this problem with my 2002 w902, lhd french registered, but turn key no click and warning lights except for glow plug, oli pressure and handbrake turn off. There is no current going to the starter trigger so I think it is a sevurity system fault. I have looked at your fuse block locations but mine seem to be different to your diagrams, the one under the steering wheel and under the side of the drivers seat but do not hold any relevant fuses or relays. The strip of relays under the front of the drivers seat are arranged very differently. In the past if for some reason the motor stalled it would have the same symptoms but after one or two more tries it would start again as normal, I thought that there may be a system to stop using the starter when the engine is running but do not know if this is the case and if so where would I locate the system, thanks, Michael
This actually sounds like it could be a simple dirty battery post or poor connection at the other end of the battery cables. Or, it could also be a internally shorted battery.
You will eliminate the battery end of the cables and the shorted battery if you attempt a jump start from a known good battery.
 

mhobson

New member
Thanks but new battery this year 100 ah Varta, clean connections vaselined when fitted, showing 12.74v, new alternator last year, only the second time in 8 years it has let me down, first was when I ignored it when it asked for a new alternator. I think I will try to take a cable directly from the battery to the trigger connection on the starter, if it turns over but doesnt start it suggests that the fuel pump cutout has received no current and therefore is likely to be an immobiliser issue. There appears to be no aftermarket immobiliser fitted but I cannot find which relays may be associated with a security system as I said the layout of the relays under the front of the driver seat are different to the ones in the associated post.

Is there a relay or fuse for the starter circuit and if so where can I find it? I have checked all the fuses and relays I can find and where the relays have the same part number I have changed them around, I have changed the battery and also run a cable from the starter solenoid trigger connection direvtly to the battery positive and nothing except dashboard lights. HELP!
 

Cheyenne

UK 2004 T1N 313CDi
I have changed the battery and also run a cable from the starter solenoid trigger connection directly to the battery positive and nothing except dashboard lights. HELP!
So it does not even turn over when directly powering the solenoid? If so you either have a duff battery or your battery to engine earth is faulty.

Can you measure the battery voltage when trying the direct connection to the solenoid please?

Keith.
 

mhobson

New member
OK I have managed to get the starter working by taking a cable between the starter solenoid trigger and battery positive, but the engine will not run so the fuel cutoff must still be shut therefore the problem must lie with the engine start security system. There is no aftermarket immobiliser, could someone direct me to the relay involved with the starter circuit please?

I have been reading all the threads about the starter relay and looking at the pictures but I am lost, my relays seem different and fewer. At the underside of the fuse block below the steering wheel are three small grey relays, when you open the cover at the side of the drivers seat there is a block with just one fuse and a large black relay. Under the front of the seat looking forwards there are two large yellow relays together and to their left five small grey relays. Apart from the glow plug relay under the battery I can find no others.
 

Cheyenne

UK 2004 T1N 313CDi
Most of the posters on here are from the USA and their Sprinters are VERY different to our European spec Sprinters.

The three small relays at the bottom of the fuse block are the ones being referred to here. The middle one is the ECU fuse which is a possible cause of your no start. Try swapping it with either one of the other relays.

Keith.

Fuse Block Stg Column.jpg
 

mhobson

New member
The three small grey relays below the main fuse block and the five grey relays under the drivers seat all have the same part number, I swapped them around yesterday, no change unfortunately, I have no idea what else to try.

Could it be that the main ecu has blown, I have not heard of it on cdi vans but I know there were a load of ecu problems on the pre cdi 310 and 312 vans.

The three small grey relays under the main fuse block are the same part number as the 5 grey relays under the seat, I have swapped them around but the same fault persists, I wonder if the ECU has blown?
 

Midwestdrifter

Engineer In Residence
ECU failures are pretty rare. Can you communicate with the ECU/ECM with a scan tool?

Your van should have chipped keys. Since you are not getting a start error on teh instrument cluster, you most likely have a problem in the following areas.

The start contacts on the ignition switch are not working.

The starter trigger wire is not providing enough current to actuate the starters solenoid. This can be caused by a bad engine ground strap, corroded connections etc.

The starters solenoid is jammed, or the contacts are burnt. You need to investigate if the starter relay is activating, and if so, is the starter solenoid getting power on the trigger wire.
 
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mhobson

New member
Thank you midwestdrifter, yes I think you are right that a scan tool is what is required, I only have one for Audi/VW. As I said when I turn the key to start position no current flows to the solenoid trigger connection, but when I connect the battery directly to the solenoid trigger the started works correctly but the engine will not run so I suspect the fuel cut off has not opened so it is more a security starting issue. I have phoned an auto electrician who suggested I disconnect the battery for 10 minutes and then reconnect it, which can sometimes reset the ECU but alas no go. I hope to get him around with his scan tool early next week.
 

Skippy and Emu

Active member
My Sprinter has had the same problem for a number of years. Still unresolved , I just work around it.
The ignition has 4 positions. Off, accessories, run and START. Mine will start if I apply power direct to the solonoid AT THE SAME TIME AS I HOLD THE KEY IN THE START POSITION . Usually takes 2 people to achieve this initially, until you can get something more permanent wired up. Good luck, I have given up wasting time trying to fix mine.
 

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