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95 S500 02 S430
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9 Posts
Discussion Starter #1
Hello all, a few days ago i parked took care of my business and returned to my 95 S500 only to find it not cranking up. All the lights on the dash came on but the car does not turn over at all. After a few tries and maybe 5 minutes it started and drove fine. The next time I shut it off the same thing happened, nothing for a while then it started and drove fine. I went thru this forum and tried quite a few things but still nothing. I removed and cleaned the K38 relay, it clicks when I turn the key but still no crank. The lower wire harness was replaced by the previous owner, i inspected it and it is in pristine condition. I am at my wits end on this one, anyone with the experience please help, Thanx in advance.
 

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1982 500SEL; 1987 Mazda B1600; 2001 Holden Vectra 2.6L
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111 Posts
I dont have any experience with your model in particular but every time Ive had similar issues it has been the starter motor solenoid. If the dash lights are not dimming at all in the start position then its pretty much definitely that. Shouldnt be too expensive in parts but could be a mission to remove and replace.

Otherwise there might be a immobiliser system I dont know about starting to pack in.
 

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Outstanding Contributor Always Remembered RIP
216 with everything. 2002 SL500 with everything. 2009 SL500 with everything.
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6,543 Posts
The output from the K38 goes to the small wire on the starter motor, you do need to check to see if you have 12v when cranking, if you have the starter motor is faulty. If the K38 is working, then I think this is fitted after the lock out switch on the gearbox, but not sure on that one
 

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1995 S500 coupe, 1990 Mazda Miata
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694 Posts
Another possibility is the switch on the side of the transmission. Next time it does it try moving the shifter to neutral and trying it there. Sometimes the contacts in the switch get dirty and the car thinks it's still in gear. My guess is the starter has a bad spot on the armature and needs replacing.
 

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95 S500 02 S430
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9 Posts
Discussion Starter #5
Hi all, I appreciate all the responses. Here's what I've already tried, the wiggling of the shifter, the K38 relay, trying to crank with the shifter in the neutral position, reprogramming the key, checking the lower wire harness (it has already been replaced ). The starter problem in my experience should dim the lights on the dashboard, the lights does not dim. This problem behaves like some form of lock out like the immobilizer, or neutral safety switch. Also, can the crank position sensor cause a problem like this or would it turn over and just not fire? All suggestions are greatly appreciated as they all help with the process of elimination. Thanks guys
 

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1995 S500 coupe, 1990 Mazda Miata
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694 Posts
A bad crank sensor would just not let it fire, not stop it from cranking. I had a bad starter on mine, very intermittent, but when it acted up the lights would not dim upon trying, occasionally it would click on the first try and then nothing after; it would light the dash lights but no crank whatsoever. Next time it does it, if you have help have someone hold the key to the cranking position and hit the starter using a bar and a hammer; you can sneak around the heat shield just barely. Good luck!
 

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95 S500 02 S430
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9 Posts
Discussion Starter #7
Thanks a lot 95scoupe, i am now waiting for a friend to come over and turn the key for me while I check the starter solenoid for 12v on start position. Will let you know how it works out, again thanks a million
 

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95 S500 02 S430
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9 Posts
Discussion Starter #8
Hello again, did the starter test, no power coming to the small wire on the starter when the key is in start position, this leaves me to believe the ignition switch has gone bad. Found a thread on replacing it so I started to take it apart, not done yet tho, (tricky job)will update when complete
 

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Greek God of the R129
SL500-500SEL-190E
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8,391 Posts
Try my trick.

Move the steering wheel in/out, up/down.
Now see if it starts.

If yes, replace the ignition switch.
That will get you a few times home.. ;)

I run for weeks, then I replaced it. Lol.

Regards,
aam.
 

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140 600 1991
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221 Posts
I may add another persepctive:
had the same, and changed NSS (as suggested by the dealer when shifting N/P was not helping), then the issue came back once unexpectedly (which made me mad) and then I went to another place for verification, they analyzed all connection paths on diagrams and decided to try to see blades in the box under the plastic cover where you connect the diagnosis device. Then they saw that some relays had cold welding (=bad connection). And apparently these relays are on the path of starting. So they welded them again and "repaired".

It does not mean that this is the cure in all cases - but the problem has disappeared in my case (is not back ever since...).
 

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1993 Mercedes-Benz 300SE & 1998 Mercedes-Benz C230
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257 Posts
If your dash board lights go on but no starter, do not rule out the security module. Try to lock & unlock the front driver's door & see if the starter turns over.
 

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95 S500 02 S430
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9 Posts
Discussion Starter #12
Hi everyone, thanks for all the insight. I am making this post to inform you all I identified what the problem was with help from someone else on this forum that posted some information on another thread. I did not make a mental note of the title of the thread or the name of the author but I think it was Gilly. If you ever read this Gilly, thanks a million you are a life saver. Apparently this model is known for ignition switch failure, (circuit # 50 power to small wire on starter solenoid) so is the R129 and many other models which uses the same ign. switch. So, FYI if u ever have the same problem, check out your ignition switch (the electrical portion) which by the way is a mission to replace. I did mine myself and now I am back on the road. Thanks again for all the responses and advice it all helped piece together the diagnosis and saved me a ton of money for which I am eternally grateful. V
 

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95 S500 02 S430
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Discussion Starter #13
This is in reply to 95scoupe question about circuit 50. The number 50 is written on the switch, it also was refereed to as circuit 50 by a MB mechanic I had a conversation with. Also I saw the use of that circuit name to refer to the circuit that sends the signal to the small wire on the starter solenoid on another forum. I hope I answered your question.
 
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