Replacing Battery In 92 500SL

[sldan]

My 1991 300SL had a problem with warning lights being on, I forget which ones since it was a few ago, but a new instrument cluster took care of the problem and also got rid of the wheel type odometer.

sldan

[tecqboy]

When ALL the lights come on at one time ( often at idle or low engine speed ) it indicates a bad capacitor in the voltage regulator circuit of the instrument cluster. No need to replace the cluster, as the problem is easily fixed with a new 89 cent capacitor from Radio Shack. This problem has been discussed often on the forum.

My gut feeling is that this ASR / ABS problem is electrical. Either a bad fuse or faulty connection. I don't think that the controller would fail after sitting and then replacing the battery. If that were true, every controller in my car should have failed by now, as I often disconnect the battery for extended periods of time ( storage ).

You haven't told us if you replaced / checked the fuse on the OVP relay. It's under the black plastic cover on the right side of the car between the cowl and the strut mount. You need to remove the 6 screws in the cover and lift it out of the way to get to the relay. The fuse sits on top of the relay. It's a blade fuse in my car. The OVP relay is there to protect the circuits in all those modules you'll find under that cover; like ASR / ABS.

[Don Moranville]

Thanks to all for input. Yes, I checked OVP 10amp. fuse, it was OK but, replaced anyway. Incidently 3 screws in my cover not 6. Only ABS and ASR lights stay on after engine starts and engine races or idles at aprox. 1800 rpm.