1990 W250 ABS light question

[Motorhead]

I am working on a 1990 W250 4x4 automatic. The yellow ABS light is on and also the red brake warning light. My question is, when the ABS light is on, does it also light the Brake warning light? I searched the first gen forum on the ABS light and I will check the wiring to see if that is the trouble. I checked the brake warning light to see if I could get it to go off by disconnecting the parking brake switch, the brake circuit failure switch mounted on the brake line manifold on the frame and disconnected the low vacuum switch. The light stayed on. I have good power assist on the service brakes.

 

[mweiman]

It seems to me like the abs and brake light usually come on together. Either for an abs or a brake problem.

 

[cojhl2]

I had this prob a few years back. Changing the control behind the cubby hole did not fix the prob. The problem was finally found to be a grounded wire between the differential and the control box.

 

[Motorhead]

Thanks for the info guys. I still have the dash apart waiting for a set of odometer drive gears for the electronic speedometer Automatic trans truck). I'll check the wiring on the frame. Someone before the guy I bought it from had put a large auxiliary fuel tank where the spare fits si there could be problems in that area. Chris

 

[Motorhead]

Fixed the ABS light issue. I went around and cleaned all the connections at the rear differential, the connectors under the hood right before it goes into the cab. I also pulled the glove box out and disconnected and re-connected the ABS box connector. ALL GOOD!