Here is an easy test to determine if the engine to body ground is the problem. Put a VOLTMETER with a lead on the -batt post and a lead on the block. Have someone try to start. If the voltmeter reads 12V you have an open ground somewhere between the battery and the engine. I had this problem on my sd. If this test passes check your NEUTRAL START SWITCH. Try moving the gear selector around when it is not working (P and N are start positions, try nearby slots)

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1983 Mercedes 300SD
1987 Mercedes 300SDL
2001 VW Passat 2.8 AWD
2007 OM642 Jeep WK 4x4

On roughly the 5th or 6th start I made this morning, nothing. Prior to that starting was instantanious. I stopped mid morning at an antique auction, didn't stay but 5 minutes, went back to the car, nothing. I would figure it is a ground problem also, and that a change of temperature might allow a start up. Hope so, will go there just before dark and give it a shot. If it won't go, I'll give it a tow and work on it Monday. I should mention that I gave the cold engine a bath last night. Squirted it down with "Zap", and then gave it a high pressure hose cleaning. It won't run, but it really looks nice!

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I do apologize for hijacking this thread, but my problem is exactly the same. So last night I went to the Fair Grounds and attempted to start the 85. No sucess - not even a click. Well, I had taken a tow strap along and so I tied it to the back of the Towncar. At 32mph it started its happy chuckle. Drove it home and tried it again this morning, still no cranking.
However, I did the jumper wire test at the little junction box, (3 screws), just forward of the battery and it instantly fired up. That is really nice to know. I'll make good use of that when I adjust the valves. So guys, doesn't that eliminate a poor/bad ground situation? Now checking in my Haynes maual, the back up lite switch and the neutral starting lockout switch are the same. My backup lites are operating. So does that mean that my problem is either the switch or the wiring from the switch to the junction box (3 screw). I do hate the thought of fighting under the dash with a switch problem. I don't have that many joints in the hands, arm and shoulder. Anybody have a word of wisdom here? Thanks.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

It's looking more and more like the key switch.

You need to get under the vehicle and attach a voltmeter to the lead on the solenoid from the key switch. No way around this test.

Watch the voltmeter and have someone else try and start it.

If you don't get any voltage at this terminal, the key switch is intermittent.

I also win the beer.

I Went to the repair location ready to employ the advice I have recvd. I popped the top off the 3 terminal housing and shorted out the small and center lug.

I got a relay click from the drivers side fender location, a Bosch part w/the no. 001-545-98-32. I ran a Google search and it seems that it is the glow plug relay, cannot be sure though. Anyway thats all that happened...

I did unscrew and clean the terminals as well as the Ground cable from the battery, at both ends. I also took the air cleaner off and tried to reach and attack the connections at the starter but they are just unreachable from the engine compartment...for me anyway.

What does this clicking mean, Do I now just short out the starter solenoid, if I can somehow find a way to reach it?

What do you all think is next?

Thanks.

I can't figure why the glow plug timer 001-545-98-32 would activate (relay pull in) when the starter motor is supposed to pull in, unless there is a bad ground from the engine to the frame.
You need to check the engine ground strap next. The solenoid should have made a clunk and the starter turned over the engine when those points were touched on the terminal strip.
It is possible that the solenoid is bad, it has contacts that are made and feed the electrical motor, how the GP module is affected I don't know
This is getting interesting!

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Is this the strap directly from the engine to ground or from the battery - term. to ground, because I did undo battery to ground cable, cleaned, roughed it up and re-connected securely...

In response to the key switch suggestion, I do not have the key available, it is in the repair shop- locked on Sunday. But, I did have a keyswitch problem before (steering wheel locked up) which a new key cured...a clue?? Could it be that if the key swtich were screwed up that some of the connections on the key switch, which activates the glow pug at position #2, are somehow messed up and now the current, when those lugs are shorted, is going to the glow plug relay instead of starter solenoid?

Also, noticed that when I unscrewed the lugs (3) to clean them, and reattached them, I heard a sparking sound when reconnecting...as if current were being drawn from somewhere.

The next time you turn the key and nothing happens...

Take a pipe or breaker bar and reach down to the (from under the hood) solenoid and tap it about as 3 times as hard as you would to break an egg, sometimes a bit harder

Then turn the key. If the starter works your solenoid is hanging up.

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1980 300TD-T (82 Turbo and Trans) 159,000 Miles "Jackie-O"
1983 300SD 272,000 Miles "Aristotle"
1987 Jeep Wagoneer Limited - keeps the MB's off the ice and out of the snow
1994 BMW 530it

I would love to do that but as I mentioned the turbp-charger is in the way, from the engine compartment, of gaining access either touching and even viewing the starter/solenoid.

I am afraid at this point, if I did have access to it I would probably wack it harder than you would an egg!!

However, I am going to really piss off the mechanic at my repair shop tomorrow and hit him with all these suggestions...I know they love that!

Keep you posted.

was the bet that the original poster's problem wasnt a ground issue or that it couldnt be a ground issue because it was intermittant?

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

We have a 300TD and I can get to it. I carry a pipe (and use as required..lol) Are you sure you can't? Kind of between the right corner of the battery and the rear of the intake?

Don

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1980 300TD-T (82 Turbo and Trans) 159,000 Miles "Jackie-O"
1983 300SD 272,000 Miles "Aristotle"
1987 Jeep Wagoneer Limited - keeps the MB's off the ice and out of the snow
1994 BMW 530it

Its under the turbo...and w/out the aircleaner removed it is not visible at all. I could feel for it, and eventually "brail" my way there but w/a pipe or someother device in hand, I don't know...you may be more dextrous than I am?

Noonetheless, it may appear a little less than dignified to be wrapping under the hood everytime I want to start it, although it might be a way of diagnosing the problem.

Case in point, as I was working on the 300DT and minding my own business today, when some guy walked up to me and my son and started lambasting about how inferior Mercedes (referring to SL600) are to his Mitsubishi 3000GT...I just politely aknowledged his right to breath and do drugs and carried on... We get a lot of reverse "snob factor" because of that emblem dont we???


DiesleDieHard: I fear there may be some really funky electrical issues going on here..Just a question, is there a fuse of something between the keyswitch and the starter solenoid. This car, in the past year has developed a vicious problem with intermittant fuses (in the fuse box) and I keep having to rotate them (all) at various times...Its a pain but there are not too many options...as I have already replaced them all with new, glass fuses which fit better and make better contact it seems.

Not to throw a million questions out there but, how do I also stop my brake resevoir from leaking- badly. I have replaced, or so they said they did, the gasket/grommet/seal between the res. and the Master cyl. It continues to seep?

Thanks all for your help...your continued support is appreciated!!

have you cleaned the contact points in the mount?

if not take a small pocket knife and twist on each end of each fuse and clean the contact area really well.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The original poster, me, did not place any bets, as I do not know enough about this problem to be that brazin...I will however let everyone know what the prob. turns out to be so that someone wins a St Polly Girl or whatever the other one wanted...

is the wild bettor.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.