What could be wrong?
 

I have a 1991 300 SE. Dealership and indedpendent
mechanic cannot find the problem with ABS/ASR. When brakes applied, front of car seems to slide at the end of braking. Can't really knwo if ABS is working or not because bulb in the cluster is burned or the previous owner disabled it to sell the car to a stupid man like me.

HELP HELP

Are you saying the brakes stop working? At what speeds does this occur? Why do you think ABS system is involved? What tests have the other mechanics done? Have you searched?

Having a bulb not work is not a permanent disability - a new one can be installed.

Your description of symptom could be interpreted as an unintended ABS application. If it happens below 10kph then it won't be recognized as a fault. If you wish to check the system or relate to a real application, find a grassy field and drive at about 5mph and slam on the brakes. The pedal should pulse at you. A single ABS presure intervention can seem like the brakes released.

If this seems to be the issue a speed sensor will likely be the problem and a close look at their signals will be required to evaluate.

I don't think that brakes aren't working, I think they are, but the wheels do lock and slide, it gets very worse when the road is wet due to rain or something. The mechanics did not do any test, they just said put it into the computer to check for errors, in my place there is no reliable place where I can do such a job of testing for errors. I searched everywhere for any clue but really couldn't find one.

How to check for the signals of the speed sensors? can you please elaborate on that point? How to check for the signal?