Kenny Amado

Howdy folks!

I'm relatively new to the forum. So I wanted to say Hi to everyone. I also wanted to see if anyone had any Ideas on some issues that I am having. I bought my 91 500sl about three or four months ago. I got it for a pretty good deal, well below blue book value. I'm starting to see why I got such a good deal lol.

The previous owner gave me a laundry list of things that were wrong with it, but its all been pretty easy to fix so far.

I have rebuilt two of the hydraulics for the Soft top. * the ones above the windshield* The instrument cluster was not working, I replaced a couple of conductors, and it started working just fine.

My newest problem is making my head hurt. The center console, had a few of the buttons pushed in. One was the button to activate the convertible. This afternoon I decided to take out the center console, and fix the buttons. Everything was going smooth until I heard the buzzer on the driver door go off. Since, I got the car, when you open the driver door, if the lights are on or not, if the key is left in the ignition, the buzzer didnt sound and the convenience light that illuminates the floor wouldnt turn on . So when it went off I thought it was odd. Once I got the console put back together I went to turn the car on. This is when all hell broke loose.

I got disco dash again. * i just fixed this issue* my tach, speedometer, gas gauge, mpg, and clock all stopped working but all the hazard lights are going nuts. My blinkers stopped working. When I activate them, the convenience lights on the doors blink and the lights on the dash blink, but no blinkers. When I turn on the hazards the same thing happens, The door lights blink the light under the dash board that illuminate the floor blink, but no blinkers. Once i activate the hazards, i cant get them to turn off, Unless I turn the car off and on again. My Radio stopped working. Its just cycles through the welcome screen turns off, and turns back on. The car is also idling differently than what it was before the dash and blinkers went buts.

I have no idea where to even start at trouble shooting this issue. Im getting a bit fed up with th?ese electrical gremlins running through my car. Any Ideas on what could have caused this, and what I can do to fix it

I hooked it up to my OBD1 Reader and got a few faults .

Socket 6 I got
9 - SRS Warning Lamp (with flashing SRS warning lamp Impulse counter scan tool button held too little time to read out the DTC memory or too long to erase DTC codes. Reread codes.)
2 - SRS Control unit self test failure
3 - Driver Airbag squib
8 - Voltage supply interrupted

Socket 7 just shows a cosntant light, no blinks - im not sure what a constant light means. If any one could shed some light on that I would really appreciate it! My Roll bar is stuck in the up position. I have tried holding the roll bar button up for ten seconds and nothing. The hydraulics do not look like they are leaking for the roll bar. I can not get it to move for the life of me.

Socket 11 also runs a constant light, I have never been able to get the alarm to sound. I assume this has something to do with the VATS. The previous owner stated he has issues with the vat, he didnt go into further detail, He said he installed a push button. The car has been working fine. I turn the key on, and then push the button, It works.

Socket 14 I got quite a few faults.
4 - Output for oxygen sensor heater control defective ( she has been idling rough)
5 - Output for air injection pump control defective
6 - Output for kickdown switch control defective
12 - Output for A/C compressor control defective
13 - Excessive A/C compressor clutch slippage
3 - TN/TD signal (RPM) interrupted


Any input is greatly appreciated. Thanks

MJ50

moved to R129 forum...

Pazo

Just a wild guess Kenny but check your overvoltage protection relay (OVP).

Tin solders in the relay are known to crack and cause "crazy electrical issues". Re-soldering the broken joints could solve your issues. Or maybe you've already checked your OVP?

Good luck!

bobterry99

If you get a steady light either: (a) you are not following proper procedure, or (b) for some reason the controller is not outputting diagnostics.

You should suspect your OVP relay. But taking it out of the car and looking at it is too nebulous for me. Instead, locate the round diagnostic connector by the ABS hydraulic unit and measure the voltage between sockets #2 and #3. With the engine warm and idling you should have 5-9 VDC.

Erase all of the codes you found, drive the car a short distance, re-read the codes, and report what you have.