Before I'm advised to use Search -- the term "ABS" is deemed too short by site mods, so it is automatically removed from Search terms. Dumb site rule for Search IMHO.

Anyway, my yellow ABS light is on along with my red BRAKE light. I replaced the rear ABS sensor this week when I sxerviced the diff, no help in turning the light off.

Can anyone recommend a step-by-step method to troubleshoot?

 

I have a 1990 B250 318 5.2L with the exact same problem. I too purchased a new sensor and replaced it but didn't have any luck. Any insight would be great.

 

I'm fairly certain that a fault in the ABS will not turn on the red brake light, only the ABS light. That means the problem is not with the ABS, but rather with the main brake system. Check the proportioning valve to see if the button on the end of it popped out. If it is, press it back in. Also make sure your e-brake is off, or the switch for it is operating properly.

 

Took everything apart today for a closer look. E-brake switch is OK. This van has a nice plastic tray with a drain hose underneath the battery, so the underside where all of the ABS stuff is located is really clean.

I don't see that my proportioning valve has any type of a reset. No place for anything to "pop" out based on close inspection.

Unplugged all of the electrical connectors and the contacts seem fine. Applied silicone grease to everything and replaced the connectors.

ABS & Brake lights still on.

Ran to the local junkyard and pulled an ABS module (black Kelsey Hayes box that sits on the same bracket as the proportioning valve) and swapped that in.

ABS & Brake lights still on.

I also have the entire ABS valve setup from the junkyard van. Don't really want to go through the drill of swapping that out but it seems to be the only thing left to do. Maybe I'll try bleeding the system once before taking everything apart again.

Opinions?

 

If you take the wire off the proportioning valve and then turn the key on, do the brake and ABS lights go out?

 

my 1992 B250 318 conversion van has no ABS

 

We should ask nibroc - oh wait, his van doesn't have ABS.

 

Removing the 2-wire connector from the front hydraulic block does not turn the lights off. I'll have to wait until I have time to remove the horn plate to test the 4-wire connector at the rear of the ABS module.

 

Thanks for sharing!

 

Disconnecting the 4-wire connector between the valve and the black plastic ABS module did not turn the light off. Something wrong at the rear axle? I already replaced the ABS sensor in the rear differential.

This ABS problem is officially beginning to annoy me.