1990 GMC V1500 Jimmy Flashing Brake Lights

1990 GMC V1500 Jimmy 350CUI TBI TH700R4 NP241 10B front/rear 3.73 front/rear ABS rear - in working condition (maybe, was until the following incident but haven't tested it since so it may still be working who knows....)

After an extremely forceful application of the brakes at about 55MPH that locked up the fronts and I'm sure started to utilize the ABS in the rears, my brake light has been on steady for about 1 week. Just after the incident I stopped and tried removing the 1 wire that goes to the proportioning valve, and this does NOT turn off the light so I don't/didn't think it was a pressure thing. I thought my parking brake switch was out of alignment (lifting up on lever doesn't fix it) and just kept on driving it. I haven't checked the p-brake switch though.

This morning it started tweekin out, thought maybe it would go out (flashing on and off randomly) Then it got rythmic;

7 short 1 long 7 short 1 long etc.

Turn off the truck, and put the key in "run" and it does the same thing. NOTHING has been jumpered AFAIK, so I don't have the truck in diagnostic mode - unles it shorted somewhere in the loom.

Everything seems fine in operation?? I'm in work right now so I can't consult my repair manuals.

GMC Gremlin

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GMC Gremlin
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P.S. I mean the warning

BRAKE ( P ) ( ! )

light, not the brake lights you would see outside of the car. JJJJJJJJJJJJJJJJJJJJJJJEST to make sure. The subject I chose sucks!

GMC Gremlin

Reply to
GMC Gremlin

Unplug the connectors to the RWAL module that sits right beside/under the master cylinder. Plug them back in after about 30 seconds...see if the light goes out. These were famous for setting false codes. If the light comes right back on, probably pretty sure that you have an actual problem.

Ian

Reply to
shiden_kai

So the computer by the MC, that has a bunch of wires, right? NOT the proportioning valve with 1 wire.

GMC Greml> > This morning it started tweekin out, thought maybe it would go out

Reply to
GMC Gremlin

Yes, there should be two connectors at the module.

Ian

Reply to
shiden_kai

How do they come off? They both are blue and white. It looks like the white pin is a "safety" that needs to be removed before the connector can come off? Just don't want to break it since the white bit wasn't coming off too easily.

GMC Greml>

Reply to
GMC Gremlin

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