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View Full Version : Van not turning over, intermittent fault. Please HELP


SR_James
04-25-2016, 01:18 PM
So I'm having an intermittent starting fault with my van.
It started happening the other day and is getting worse. It probably fails to turn over more than half the time now.

Usually when you turn the key the glow plug light comes on and there should be a click from a relay near the fuse box under the glovebox, followed by a whirring sound which i assume is the fuel pump priming???

However often my engine temperature warning light is on and there is no click from the relay and the glow plugs don't come on. This happens several times until she miraculously decides to behave and starts fine. Sometimes this can take several minutes.

My guess is a bad relay in the SAM unit under the glovebox, does anyone now if that could be the problem? And if so which relay it is?

In the last few days I've also noticed she idles very badly occasionally, with the revs constantly going between 800/1000 rpm. I doubt this would be related if the problem is only a relay, or perhaps my starting problem is more complicated than I'm hoping and it's causing the bad idle?
Like a crank/cam position sensor??

Lots of questions there I know, all help is much appreciated.

Thanks a lot

SR_James
04-25-2016, 01:21 PM
Forgot to mention, I have a cheap bluetooth OBDII reader and the torque app and cannot see any fault codes either when running or failing to start.

Aqua Puttana
04-25-2016, 01:50 PM
Forgot to mention, I have a cheap bluetooth OBDII reader and the torque app and cannot see any fault codes either when running or failing to start.
Unfortunately it is common for these no crank issues to not set a DTC which would trigger the MIL aka CEL dash warning.

The auxiliary electric fan running is a clue that your problem is ultimately causing a module communication issue, or lack of communication. When the ECM aka ECU doesn't get an engine temperature signal (CAN bus communicated) the ECM assumes a worst case high temperature. That condition default response is to run the aux cooling fan.

:2cents: vic

hulagun
04-25-2016, 03:25 PM
So I'm having an intermittent starting fault with my van.
It started happening the other day and is getting worse. It probably fails to turn over more than half the time now.

Usually when you turn the key the glow plug light comes on and there should be a click from a relay near the fuse box under the glovebox, followed by a whirring sound which i assume is the fuel pump priming???

However often my engine temperature warning light is on and there is no click from the relay and the glow plugs don't come on. This happens several times until she miraculously decides to behave and starts fine. Sometimes this can take several minutes.

My guess is a bad relay in the SAM unit under the glovebox, does anyone now if that could be the problem? And if so which relay it is?


SR_James,
I just went thru this - you can search for my posts using the blue bar. I recommend searching for "no crank" as it appears you do not have the common SKREEM "no start" condition. You will get more info searching that way. Also - You will surely get better help if you also PLEASE fill out your bio info or signature line (or both) so us folks (who like to help) can know what year /model van you drive. Thanks!

SR_James
04-25-2016, 04:59 PM
Thanks both.

I'm pretty sure the fan doesn't run, but unfortunately I'm away from the van for a few weeks now so can't double check.

I'll get that bio done now, thanks for the tip.

Bobnoxious
04-25-2016, 08:01 PM
So I'm having an intermittent starting fault with my van.
It started happening the other day and is getting worse. It probably fails to turn over more than half the time now.

Usually when you turn the key the glow plug light comes on and there should be a click from a relay near the fuse box under the glovebox, followed by a whirring sound which i assume is the fuel pump priming???

However often my engine temperature warning light is on and there is no click from the relay and the glow plugs don't come on. This happens several times until she miraculously decides to behave and starts fine. Sometimes this can take several minutes.

My guess is a bad relay in the SAM unit under the glovebox, does anyone now if that could be the problem? And if so which relay it is?

In the last few days I've also noticed she idles very badly occasionally, with the revs constantly going between 800/1000 rpm. I doubt this would be related if the problem is only a relay, or perhaps my starting problem is more complicated than I'm hoping and it's causing the bad idle?
Like a crank/cam position sensor??

Lots of questions there I know, all help is much appreciated.

Thanks a lot

Greetings:
It is least expensive and simple to begin by checking the battery condition and all associated connections.

Most intermittent electrical problems may be the result of and traced to faulty battery connections, especially the ground or negative battery cable.

Are the battery terminals clean and tight? How about the ground cable attachment point to the vehicle's body? Even though ground cable may appear clean, remove, clean terminal and bolt with a wire brush and replace. Replace battery cable terminal clamps that appear broken are corroded.

Depending on the location of the battery it might be covered with grime carefully. Carefully remove the grime.

Purchase a battery terminal post cleaner. They are in expensive and convenient.
I have about 10 of them because I can't resist buying them for $.50 at yard sales and usually forget where I put them because I have a bad habit of not putting things back where they belong.

If the battery posts Cable terminals are corroded with a white substance be careful while cleaning because it is corrosive to metal, clothes and skin. Be certain to remove any of the substance from the battery compartment. Wear safety glasses and nitrile gloves. You can also use a solution of water and baking soda to neutralize any that may remain in the battery compartment.

Remember, cleanliness is next to godliness.

After all the battery connections are inspected, repaired and determined to be in good condition. Perform a battery State of (SOC) charge and load test. Sears and many auto repair shops will perform this test for free. Click the link for more info.
http://www.howacarworks.com/electrical-systems/checking-battery-leads-and-connections

Bobnoxious
04-25-2016, 08:23 PM
More info

http://youtu.be/MhnVZ7ZPunw

SR_James
04-25-2016, 08:27 PM
HI bobnoxious,

I don't think it's a power issue, as the dash lights up fine.

Turn the key once the van won't crank, try again a several times (maybe have to wait a while) and eventually she fires perfectly.

I understand corroded terminals could cause a reduction in current to the starter but I can't see how they would create a situation where there was either all or no current flowing.

Bobnoxious
04-25-2016, 08:39 PM
Again, the battery and associated connections are the logical, least expensive and simplest diagnostic starting point. Then continue to work your way toward the starter by inspecting wiring connection integrity.

SR_James
04-25-2016, 09:12 PM
Ok thanks.

My battery box is in the cab and is genuinely like new inside, I'll check the earth when I can though.

I don't think the relay under the glove box would not energise due to lack of power to the starter, more likely the other way around, but maybe.

I am beginning to wonder if it's something to do with having a split charge relay fitted, I've seen on some other MB forums a lot of people with camper conversions complaining about similar problems.

showkey
04-25-2016, 09:50 PM
A recap of what others have found on the "no crank"....
Many of us have not actually found the smoking gun but the problems sorta fixes itself at least for a while.

In no particular order:

Battery. ( weak)
Y cable problems
Engine ground cable
Starter failing usually solenoid related
Starter relay in the left side dash fuse box
Transmission selector switch poor connection or cable out of place ( causing starter interlock issue)

Y cable and solenoid issue seems to be most common with engine ground cable bringing up the top three.

SR_James
04-26-2016, 10:00 AM
Thanks showkey,

Does anyone have a diagram of the relays?