IGNITION ELECTRICAL ISSUE

I have a 2006 T1N 118" with 90,000 . I have a top of the line battery thats only 5 years old. My van is my daily driver and was driven last night. This morning I went to start it and the dash lights came on and I heard the fuel pump engauge briefly and after 1-2 seconds it cycled off and then back on again. If I leave the key in the POWER position it continues to cycle OFF and Then ON continuously, "Dash lights ON and OFF" (like it was connected to a slow turn signal connector). When the key is turned further to attempt to start it nothing happens. I disconected the battery for 5 minutes ( thinkinking it might reset a computer problem) but it didn't help. I'm getting ready for a major camping trip. Any and all help appreciated. Robert "Greg" Hill 619-916-7734

I left a message this morning on DOKTAR A's phone describing my problem. If there is anybody that has had this same exact problem in the past and was able to successfully fix it I'm interested in hearing what it was. I don't want to get it towed to a shop that doesn't have a clue of where to start looking. Thanks

I just checked battery with a meter and its at 12.8 volts.

Also looking for any recommendations for a good service Repair in San Diego California. Thanks

Bobsci said:

I have a 2006 T1N 118" with 90,000 . I have a top of the line battery thats only 5 years old. My van is my daily driver and was driven last night. This morning I went to start it and the dash lights came on and I heard the fuel pump engauge briefly and after 1-2 seconds it cycled off and then back on again. If I leave the key in the POWER position it continues to cycle OFF and Then ON continuously, "Dash lights ON and OFF" (like it was connected to a slow turn signal connector). When the key is turned further to attempt to start it nothing happens. I disconected the battery for 5 minutes ( thinkinking it might reset a computer problem) but it didn't help. I'm getting ready for a major camping trip. Any and all help appreciated. Robert "Greg" Hill 619-916-7734

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First make sure your battery posts and cables have a "pocket knife" shine to them. Don't use a wire brush and expect good results. Scrape some lead off. If that doesn't help check the ground cables to body and engine points for rust/corrosion. Eliminate those most common failure points first.

Gary

Bad grounds. I believe the large ground that goes straight to the firewall grounds the ECM, start there. In the service manual search for "Ground location".

Could also be dirty connectors on the power distribution center, the black box mounted to the battery. Clean to a shine as GaryJ stated. Or a bad fuse panel #1? Check voltage where the red cable fastens to the fuse box under the steering wheel.

I cleaned and checked battery connections. I then ran over and asked a local Mercedes tech where he would start looking given my problem. He said he would probably end up in the distribution/Fuse box under the steering column. So I went home and removed the distribution/Fuse box. I'm finding some green oxidation especially on the 3 heavy gauge RED power wires. I've got the box all apart on the kitchen table and I will buy some electrical cleaner in the morning and put a few hours into detailing all the connections and brass boards. Its rather in depth and I'm sure the dealer would have just sold me a new box $$$. I have more time than money. Wish me luck. The first two years of my vans life it was a Plumbers truck that had a high pressure jetter machine mounted in the rear, this created a high moisture enviorment that has caused turquise green oxidation on some in cab connections, my rear taillights are the worst.

Any of the relays in the game could be failing to pull in.
The green (it may be copper sulfate: poisonous) oxidation probably isn't a direct cause...

--dick

Just replace the whole fuse box, it cost about $100 from Europarts of AD. I took mine apart a couple times to chase down a no start problem and ended up just buying a replacement.

travelbuds@verizon.net said:

Just replace the whole fuse box, it cost about $100 from Europarts of AD. I took mine apart a couple times to chase down a no start problem and ended up just buying a replacement.

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I repaired my FB #1 mostly because I'm hard headed and didn't want to give up.

For the price it really makes more sense to just replace the entire FB #1. The FB #1 is a true module with on board electronics. The new part comes complete with all fuses and relays.

Replacing the FB #1 eliminates a bunch of guessing. If it doesn't cure the issues then at least it will not be a focus when you are paying for more troubleshooting. The price of the part is likely less than you will will pay a dealership to pull your Sprinter into the service bay and connect a scan tool.

The above said, my 2004 has been working flawlessly since I made my blue wire jumper repair. (Knocking/touching wood furiously as I typed that. )

vic

Some info is here.
https://sprinter-source.com/forum/showthread.php?t=7909

5k mikes ago or so my ground strap from the battery went bad and exhibited similar behavior. I thought it might be the fb#1 but that wasn't the issue. If you don't want to spentd the $15 and spend 10 minutes putting on a new and perhaps thicker ground wire, you can test by jump-starting the battery but put the ground from the jumper cables on the chassis instead of the negative post of the battery. Might be worth just changing it out though to rule it out. Could also be the ground strap from engine to chassis...

I spent the first half of my day replacing the Fuse Box/ Distribution Box under the steering column with a new one I bought online, $100 included shipping. Most of my time was spent cleaning all of the plug connectors ( I was very thorough). Sadly this DID NOT fix my problem, Ugh! I'm glad I did it anyway as it was pretty green in places. At least I ruled the Box out. So I guess I'm going to be Checking all my grounds and if I can't find it I will have to be towed to Mercedes San Diego and pay $133 an hour to have it diagnosed.

Vanski, My battery is fully charged could I just use one of my jumper cables and run it to my battery Negative post ( leaveing everything connected) and the other end to the engine block or frame to check if there is a bad ground and try to start it. Then if it starts I would know that its a bad ground in my system? I'm not very good with vehicle electrics, I just wanted to run this by you and so I don't do some thing stupid and short out my electrics.

Using a jumper cable is a perfectly good test ... just make sure it's not going to hop off and contact something "embarrassing" ... (such as the positive post, starter positive post or the fan blades)

--dick
Murphy's Law of Selective Gravitation: things will fall where they'll do the most damage.

autostaretx said:

Using a jumper cable is a perfectly good test ... just make sure it's not going to hop off and contact something "embarrassing" ... (such as the positive post, starter positive post or the fan blades)

--dick
Murphy's Law of Selective Gravitation: things will fall where they'll do the most damage.

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Thanks appreciated

I removed and cleaned up my ground at the battery terminal and the fire wall (not dirty or oxidized), I sprayed contact cleaner on the copper ground from the engine to the frame (not Dirty or oxidized). I then ran just one jumper cable from the engine block to the fire wall ground post. When I turned the key I got what appeared to be a normal starting sequence then when I turned the key to start it went to "Start Error" on the dash and wouldnt turn over. I reposistioned the ground to the frame and other locations but now its back to flashing the dash lights on and off at 1 second intervals. I'm starting to think its a faulty relay somewhere, because of the OFF and ON at a perfect rhythm. Dang! I thought I had found the Gremlin.

Bobsci: In my situation it was the actual ground wire from the negative post of the battery to the ground location at the firewall that was bad. The actual black OEM MBZ wire. I was able to isolate this by completely disconnecting the negative battery cable and then jumping from the negative post to the chassis. This test is not perfect since the sprinter can be very sensitive to voltage drops and since you are increasing the run with the jumper it will decrease the voltage during cranking, especially since the sprinter requires an abundant amount of cold cranking amps from the battery. I have some pretty heavy duty jumper cables which is why I think the test worked for me...

Your battery does show 850 cold cranking amps or more on it, correct??

Just to rule it out, I would replace the ground wire from the negative post of the battery to the ground location (firewall). 10 minutes, $15.. why not?

Also keep in mind that with all this cranking you might have drained the battery. And if it's drained pretty far down it's going to take another vehicle with a beefy electrical system to properly start it. If you have a charger, let it charge over night.

Given all the oxidation on the FB#1 I'm surprised that didn't fix it. That still could be the issue as there may have been areas you couldn't clean properly.

You're on the right track.....

You're in the SD area.. These guys kick butt - https://escondidogermanauto.com/ especially if they still have the sprinter tech who's been putting up various youtube videos.

Had the exact same symptoms a while back. Turned out to be the starter relay in the box under the driver seat. For the price of the relay it might be worthwhile to roll one in and see if it helps.

Thanks Faraday, bought a new starter relay today, NO CHANGE, All my electrics are turning ON and OFF as if connected to my turn signal relay. I bought a tub of vaseline and I'm being towed to the San Diego Mercedes Sprinter repair shop that is separate from the main dealership, Hoping they have the correct computer to quickly find and fix my problem. I will post my results to help others in the future.

The problem described is not likely to set a useful code, real mechanical diagnostic techniques will be required. My money is on bad ignition switch or fuse block 1 (that thing can be a dirty bastard).