A little w124 weirdness
 

Guys, while driving day before yesterday, the ABS light came on, and the tach dropped to zero and the AC clutch disengaged. About 3 minutes later, the ABS light shut off, tach came back, and AC clutch re-engaged.

Yesterday, the AC clutch again disengaged, but came back about 3 minutes later. No ABS light, and tach kept working.

So my question is, it this a sign of a failing Klima or OVP relay?

Thanks!

I'd bet money on there being a bad ground or low battery voltage. Start checking connections for corrosion including the battery posts.

Here is an update. This morning, after work...I work nights...I started the car, and all warning lights would not shut off. Shut down, restarted, and all warning lights again stayed on, but the tach worked. So, I ended up driving home. The warning lights then began to flash, then flasehed dimly, then shut off. Got home, shut down and restarted the car, and then ABS light and no tach. A/C clutch never engaged.

I will check all the ground connections. I have to clean them once per year on my old Dodge Cummins.

Thanks!!!

Check voltage regulator on your alternator. Classic symptoms. If replacement does not help, you may want to have the alternator checked and OVP relay too.

I will be working on it on Saturday. I do hope it is something simple...

Time for new thread. Now that I was able to see stuff in the daylight, there is no tension on the serp belt...