Stranded. instrument cluster issue in 2007
 

I am away from home with limited tools and no wiring diagram. I do have a DVM. I thought it was the battery, but charging it overnight and also trying another known good battery didn't help with the no crank. It's an 83 300D turbo. All fuses look good and have voltage on them per DVM. All electrical accesories seem to work but I am not getting voltage to the glow plugs and the starter motor will not engage. I do not hear the starter solenoid clicking either when trying to start.

Questions:

1. Is there a start relay and where is it located?

2. How is the glow plug relay powered? Is it through the key switch or through another relay?

3. Can I jump the starter solenoid without crawling under the car? (do not have work clothes with me)

This is my first Benz and I am still getting to know where things are. Any help appreciated.

Is it making ANY noise when the key is turned (clicking, etc.)? As far as I know, the starter can only be accessed from below the car (someone please corect me if I am wrong). How DIY are you? You first need to get to the wiring on the actual starter with the multimeter, and make sure that you are getting voltage on the high voltage side (with the key turned to start, of course). Try that and report back. By the way, question #2 is probably irrelivant, for you're not even cranking. If it was cranking, just not starting, THEN I would worry about the pre-glow system.

Check the 80 amp strip fuse for the GP circuit relay. It on the driver side fender, in a black box, just before the head light assembly. The starter solenoid is under the car. However you can try tapping the starter with a hammer, or try jumping the solenoid by bridging two wires, (Do not know which, as I have not done this) on the passenger side wheel well, in a small black box just before the battery.

Also, did you move the gear selector from Park to Neutral, and back to make sure the nuetral safety switch is making contact?

Start with some basics
1. Are your battery connectors tight and clean
2. Neutral Safety Switch - try moving out of P and back
3. Follow + cable from battery to starter make sure it's not loose
4. Look at ground (-) make sure it's tight

look for a 1" x 3" box on the passenger's fender with wires in it. open the little flap, and you will see some red wires and some white wires.
short two adjacent wires with car keys or a pair of screwdrivers, or a pair of pliers (I ALWAYS have my Leatherman with me!)
this WILL send power to the starter solenoid, so be SURE you have the car in park/neutral.
the glows only have power going to them, if you put the key in position 2, and you don't go to position 3 first. put the key in position 2, then test for power at the glow plugs.
John

Check the wiring distibution block on the passender side fender in front of the battery (large wires attached with plastic cover). Make sure all wiring is tight; I believe power is dirtibuted to the starter from this point.

You can bump start the car by shorting #1 & #3 at the wire junction box directly infront of the battery. Had a flip top and some splayed connectors. #1 is the thickest wire.

Where are you stranded, BTW?

Stupid question

Has the car got an immobiliser??

I jacked up drivers front with the OEM jack and found a loose ground strap bolt on the engine to transmission bell housing. It was waaay loose. I tightened it as best I can and it cranked right over.:) I am back on the road. Thanks for the help.

NO

Thanks, this is a good tip to know.

Where are you? Are you on Long Island?

No, but not far from LI in Queens. I'm back on the road now thanks. My problems started after I did a few 0-60 timed runs. See this thread for more info:

http://www.peachparts.com/shopforum/diesel-discussion/189016-engine-wont-crank.html

I suppose the extra stress from the timed runs loosened an already loose ground strap bolt on the bell housing to cause a no start and the weird electrical problems I was experiencing.

hah
 

well at aleast I learned a few things to look for and try , if ever... . :P




cheers! :book:

not any more!

tom w

Since I tightened the loose ground strap, the car now starts fine. However, there's a new problem: The coolant temp and fuel gauge are now both pegged at the upper end of the scale when I am on the hwy. When I'm stopped at a light, most of the time the 2 gauges are pegged but sometimes it jumps between pegged and normal reading.

Hey Tom, where exactly is the problem this time?:)

You don't know what I went through to fix the coolant temp and fuel gauge! I checked everything. The temp sensor is ok, the cluster has a good ground, the gauges are getting +12. The gauges work except it's indicating 80 deg and 1/2 tank too high. Turned out it was the gauge pod! I reseated the circular connector a few times which didn't help. I took it out, re-soldered every connection, found an almost melted copper trace and jumped it with a piece of wire, put it back and the gauges now read normal. What a PITA that was. What bothers me is the unlikelyhood of so many seemingly unrelated problems poping up within a few days. Hope this don't happen too often.

My guess is that they may not be unrelated. If the engine ground strap was loose, the only other path to ground could have been through the instrument cluster thus burning out that wire.
bb

That has crossed my mind. If a loose ground strap could burn out copper traces in the instrument cluster, I would call that poor design on the part of Mercedes engineers. If I am really curious, I could pull the cluster, buzz out the burned trace, draw a diagram and analyze if that is possible. Maybe next time I'm in there.

When I first saw the title I thought 'how does one get stranded with internet access?' :smartass:

I have internet access on my phone! :) As long as I have a Sprint signal, I can get help from this forum. :pleased::pleased::pleased::D:D:D

Well, you can call the ground burnout in the cluster a design flaw, but also keep in mind that when the car was new/less than 24 years old, that probably wouldn't have burned out, and definitely wouldn't have burned out as quickly.

Many things on these cars, like the vacuum lock system, can be seen as design flaws or poor design, but keep in mind that these cars are over 20 years old and it all still works. That seems to run counter to any arguments in my mind.

Then again, maybe you're right. :rolleyes:

Ahh life in the age of teckmology.:D

Got to love that EVDO Sprint service! 1 Meg downloads to a phone?? :D

OK I am done hijacking now.... carry on.....

any time to trace out the circuit and figure out why it burned? or is all working well, and you don't wanna mess anything up?

Sorry, didn't see your question till now, 7 years late. :D

Cluster has been fine since the repair and I have not done any tracing- sorry. Car sold to JB3. If JB3 saved the cluster, and if he post a pic of the repaired burned trace, there is a possibility I can trace the circuit on my 85, if both clusters are the same.

I did indeed save the cluster, where would I find the repair? is it right on back?

You'd have to take the gauge pods out and look for traces that I soldered.