I have a 90 Blazer (full size) and the brake light on that thing
constantly comes on.
Just completely redid all of the brakes, pads/rotors/drums/wheel
bearings/you name it.
Light still flashes. Im almost at the point of just taking a small
piece of electrical tape
and covering the damn light...When I bought the truck, the guy I got
it from had a dealer
go through the system and no problems found....it was driving him
To reset the brake light...I will disconnect the quick connectors at
the master cylinder/key on/
key off/ replace connectors. Or disconnect battery. From what I
understand though, if you disconnect
battery it will dump a lot of saved info besides the brake system.
However I havent had any issues
If you ever find your problem, Id be interested in hearing what it
I don't have any experience with this truck as I'm just trying to fix up
and sell the Blazer for a friend. The system is a bit different from
what I'm used to as the master cylinder does not supply the brake
pressure directly to the brakes but goes to a brake line manifold which
has the four lines to the brakes and a single wire sensor. Is this how
your truck is set up?
My guess is there's a piston switch in the manifold that will move if
there's unequal pressure in the front and rear lines and ground out the
sensor wire. It might be that removing the sensor wire will turn the
light off - but I doubt that. If it does then all I'll have to do is
find out how to reset that internal piston in the manifold. If it
doesn't then it could mean that the light is activated by the control
box - as it is your truck. I will try disconnection the switch and then
when that doesn't work, try disconnecting the battery.
The brake line manifold is interesting - it appears to have bleeder
valves on both ends. However the system works, I suspect that the piston
has to be repositioned. OTOH, it could also be that the sensor switch
has failed and has defaulted to the on position. Gee I wish that someone
could just tell me what to do. :-)
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