Hello,
We have a 1995 s320 and I have a really odd problem.
I live in southern California and it has been hot here, when the temp outside was over 95 degrees my car just would not turn over or anything. It was like the anti-theft was engaged. Once the outside temp cooled down, BAMO it would start up without any problems at all.

This went on for a couple of weeks, it would almost seem I could roll down my windows and try to keep the inside of the car cool and it would start. But I really never knew if it would start or not.

Now, today I cannot get the car to start at all, cool or not.

I have been reading the posts here for hours and hours to make sure my question was not directly answered already. Although it seems several people have had the same problem, it was typically on a different model.

I looked for fuse 5, for me the fuse 5 is the power to the rear fuse block so I am not sure what fuse 5 they are talking about. In any case I checked all the fuses and made sure they were not loose.

I understand there is some kind of Starter Interlock system in these cars. Where I am not sure, behind the glove box?

I have also tried moving the transmission selector from Park to N and again no change.

On one of the threads, a poster said about bypassing a starter relay inside the motor compartment.

I would like to try that and if anybody has any information on what to do to try and run some type of diagnostics I would so much appreciate it.

So I understand the chain of events; Starter switch, neutral safety switch and then the K38 relay (Starter Interlock system) to the starter? Or to another relay then the starter?

HELP please, this is my wife’s car and I am under the gun to try and fix things for her.

For anti-theft reasons MB used that starter interlock system 3 years.
1995 was the last year. Central locking system sends signal to K38 relay for starter.

That relay is behind the glove box, tie-strapped to the dash support rail.

Have you tried locking/unlocking?

Have you tried N instead of P? on the shifter

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Yes, I have tried unlocking and locking several times, I have tried using the remote etc.

I then tried starting in N, along with rocking the car.

Because of how the car starts when it decides to start is so strong and perfect, I have a hard time believing it is the starter motor etc.

Is there any other starter relay in the engine compartment I can try to bypass to see if I can get the starter to move?

I will get to that relay behind the glove box today and tell you what I find.

Thank you again for your information.

No other starter relay.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hello, thanks for all the help so far, today was my first day off so I decided to at least give things a try.

I removed the glove box, and behind the glove box was the air bag and what looks like a centrol vacumm type control box.

I could really not see anything past that. I would like to take out the air bag but I am not sure if that is a good idea or not.

I could see a silver relay up toward the top right back, behind the air bag. I am not sure if that is the K38 relay your talking about. It sounds like it is clicking when I turn on the ignition, but when I touch it and turn the ignition on, it does not feel like it is turning on or off. So I could be hearing a different relay.

Where is this theft control module?
Is the relay I found the correct K38?
or is that for the air bag?

Is it okay to remove the air bag? I dont want it to explode on me.

I also tried to find the starter motor and I could not even find that darn thing?
Where is the starter motor on a 1995 S320?

My first Mercedes when I could afford it was a 1982 300sd, I had that car all figured out. Very simple. I love that car and miss it!
But this car, I feel like I am in Kindergarden.

Help please, I will leave everything alone until I hear from you, I dont want that air bag to explode on me if that is possible.

Sorry I sound like a DipSHXX I just have no clue on this car yet.