'91 Suburban, Flashing brake light

[Supertrucker]

Hey folks,

Got a question that I couldn't find an answer to from searching the forums. When I bought my Sub, the brake light was always on steady. Previous owner put a piece of electrical tape over the light to cover it up. I had planned to investigate it until recently when the light started to flash. It now flashes six times and is on steady for a moment then flashes again, then repeats. Any thoughts on this? I know it does have the rear ABS, could there be something goofy with this?

Thanks for the help.

[Robyn]

There very well could be an issue with the ABS system.
I dont have a book on that year but someone here is going to have the answer.
Also there could be an issue with the pressure differential valve also.

Robyn

[Supertrucker]

Thanks Robyn for the reply. Sorry for the late response, been very busy. Anyway, I figured it has something to do with the ABS system, just not sure exactly what. I wonder if there is a way to defeat the system entirely since it isn't really a necessary item anyway. Now suddenly another problem has popped up. All of my dome lights have decided to no longer work. The fuse seems to be ok...gonna take some investigating.

Cole

[bl78ljb]

My 1990 S-10 did the same thing and it was a bad ABS solenoid. The flashing means it is giving you the code - apparently that happens when you leave the fault alone long enough (though I don't think it is supposed to). I fixed mine by unplugging the ABS computer since the rear wheel ABS never worked all that well anyway - a little black tape around the connection (not plugged in) keeps it close to the computer and clean and still passes inspection. There are codes for the ABS faults, but the easiest way to see if it is the ABS is to first unplug the harness and if the light goes off and stays off you have your answer, now if you want to fix it you have to read the codes from the flashing light. I cannot recall the codes off hand but I think they were in my factory service manual.

[Supertrucker]

Thanks Bryan, That was my next step. I figure the rear ABS probably doesn't work right anyway so it might as well be unplugged. We don't have to worry about inspections here in MN anyway.

Cole

[93GMCSierra]

Could be a ground, I dont know which style of rear door you have but I have an older hatchback gm that had a faulty ground for the rear defrost, also runs the third light, the light would lite up anytime the key was in the on position. I found and fixed the faulty ground and it works as normal.

[a5150nut]

Thanks Bryan, That was my next step. I figure the rear ABS probably doesn't work right anyway so it might as well be unplugged. We don't have to worry about inspections here in MN anyway.

Might not have regular inspections, but get into an accident and have some lawyer poking around and it all becomes your fault.