92 S-10 Blazer Sport, 4.3W, Auto Trans, electric transfer case.

The problem.... When I bought this, the ABS, and Brake lites were both on. ( got it dirt cheap) So, inspect the brakes, fronts were brand new, including calipers, and rotors. Rears... well, lets just say it was a trip to the parts store for shoes, hardware kits, and wheel cylinders. Turned drums, reassembled brakes, bled them, three of four times, over the course of two days, all should be well. But it isn't. Brake lite is STILL on. ABS lite is on, complaining about rear brake pressure. Ok, fine. The brakes work great. All four wheels. Pedal travel might be just a bit long, or, I might be to picky, in any event, the brakes work great, but, the abs is still whining. Reset codes, immediately came back. Hhhhmmmm. Tried to figger out why the brake lite stays on. Disconnected switch at prop valve, lite still on. Huh?? Grounded wire, still on..... Checked Ebrake pedal, all the way up at the stop. Noticed that someone hacked around under there pretty good, seems like there was an alarm installed, then, removed...... For the life of me, I can't find the switch that SHOULD be on the ebrake, to turn on the lite. Coincidence? Maybe, but, I don't think so.

Does the ABS pay attention to the brake lite? And then whine about brake pressures? I do not have a manual (yet) to read up on this, but, it would make a twisted sort of sense.... Currently, the abs power connecter is not. Solving one problem for the moment, but, I want to FIX this. It is rather annoying, what with me supposedly being a good mechanic and all.... Twisting myself around in there is certainly not easy anymore though... so, I have slowed down DRAMATICALLY, and can no longer do it for a living. (I found out I have MS, great fun.... story for another day though)

I am open to suggestions, insights, insults, whatever.

Thank you for your time.

 

Typically the brake light is either the parking brake or the switch on the master cylinder reservoir. You'll probably have to find the wiring for the parking brake switch and either reinstall the switch or tie the wires together.

I have assumed you have a CPI motor, but I do not think it has any bearing on the ABS/Brake system. Please find the wiring diagrams attached below. I have also included the schematic for the rear wheel anti lock system (if so equiped).

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[IMG]local://upfiles/667/53FFD26452984681A0A770035844B50E.jpg[/IMG]

[IMG]local://upfiles/667/E19BE105C0B243519309B74BF835C622.jpg[/IMG]

 

Hhhmmm, according to the diagrams (thank you VERY much) the park brake switch is nomally open. (brake not set...) so, if it were gone entirely, one would think the circuit would be open, the lite would be off, and the abs would be happy..... It is rather extremely cold out today, and is going to remain so for the next several days, so, I don't think I am going to concern myself with it for a bit..... if we get a reasonably warm day, I am going to have to have a look.

 

on that there should be two wheel speed sensors on each of the front wheels. one or both could be bad. I don't think the abs light will specify which side. I had my drivers side go bad, but lucked out. the wire actually rubbed against the wheel and shorted it out. I had a good guess which one was bad.

 

I did not get any wheel sensor codes, just brake pressure. On looking at the wiring diagrams, etc. I am fairly sure the park brake switch is the root of my problems. Just gotta get out there, and look around. GM put the switch in a spot that is CERTAINLY NOT easy to see/get to......