Parking brake issue

[zodiac572]

95 gmc c2500 Looking for some guidance with this parking brake light, ive tried the unplug the switch at the parking brake pedal ( lights stay on) tried tapping on the abs module ( lights stay on) looking to see if someone can tell me what wire is the parking brake on the module thank you

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[Road Trip]

If you could share the year, model, & drivetrain this would help us help you.

For I'd rather share specifics based on what you have vs generic info that may not be as helpful.

TIA -

 

[zodiac572]

Sorry just updated it , 95 gmc c2500, now i did just do the rear brakes and they are still a bit squishy i find, could that make the lights turn on? Should i of bled the front brake amd abs module?

 

[Road Trip]

95 gmc c2500 Looking for some guidance with this parking brake light, ive tried the unplug the switch at the parking brake pedal ( lights stay on) tried tapping on the abs module ( lights stay on) looking to see if someone can tell me what wire is the parking brake on the module thank you

Perfect. Sure enough, the '95 is the transition year where we really need to use those manuals
for best results. Let's first figure out all the different ways that your Brake Warning Light can be
illuminated, followed by a little troubleshooting based upon your recent rear brake maintenance.

According to the '95 FSM, there are 3 different items that can illuminate the light:

* Parking brake switch
* Combination Valve
* ABS system

Let's take a look at the associated wiring diagram:

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The way the circuit works is that whenever there is 12v through the "GAUGES" fuse there is 12 volts
on the brake indicator filament. However, there is no actual current flow until either the parking brake,
Combination valve, or ABS grounds the circuit. Essentially you disconnect these one at a time until
the light goes out. (And if you disconnect all three and the light remains on, then you have a chafe
between the TAN/WHT wire & ground somewhere.)

now i did just do the rear brakes and they are still a bit squishy i find, could that make the lights turn on? Should i of bled the front brake amd abs module?

This is a valuable bit of info, and would lead me to disconnect the wire from the Pressure Differential Warning Switch
on the Combination Valve first, because part of this component's job is to monitor front vs rear brake pressure,
and if there's a significant imbalance, the shuttle will move, causing the switch to close, grounding the circuit, and
the warning bulb illuminates.

Here's the part in question:

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(Did you catch the part about the only way to turn the lamp off? Post fix you have to push the brake pedal hard enough to develop ~450 PSI to recenter everything.)

****

The short answer to your question is to go ahead & give everything a thorough bleeding.
Give your brake system the gift of clean brake fluid everywhere. And after all this bleeding,
assuming the brake pedal firms up, a final firm pedal depression should extinguish the
brake light for you. (Assuming it's the Combination Valve that is providing the ground for this bulb.)

NOTE: If it's not the Combination Valve, but instead it's the ABS box, then that's a different
story. If you don't already have a set of GM Factory Service Manuals by your side, then
you can download the .pdf files that I just used to post these pages. ('88+ GM FSM links)

But given your recently opening up the rear brakes the probability is that your
Combination Valve is where the constant brake warning light is coming from.

Give this a try and let us know how it turns out.

Best of luck with your brakes --

 

[zodiac572]

Perfect. Sure enough, the '95 is the transition year where we really need to use those manuals
for best results. Let's first figure out all the different ways that your Brake Warning Light can be
illuminated, followed by a little troubleshooting based upon your recent rear brake maintenance.

According to the '95 FSM, there are 3 different items that can illuminate the light:

* Parking brake switch
* Combination Valve
* ABS system

Let's take a look at the associated wiring diagram:

You must be registered for see images attach

The way the circuit works is that whenever there is 12v across the "GAUGES" fuse there is 12 volts
on the brake indicator filament. However, there is no actual current flow until either the parking brake,
Combination valve, or ABS grounds the circuit. Essentially you disconnect these one at a time until
the light goes out. (And if you disconnect all three and the light remains on, then you have a chafe
between the TAN/WHT wire & ground somewhere.)




This is a valuable bit of info, and would lead me to disconnect the wire from the Pressure Differential Warning Switch
on the Combination Valve first, because part of this component's job is to monitor front vs rear brake pressure,
and if there's a significant imbalance, the shuttle will move, causing the switch to close, grounding the circuit, and
the warning bulb illuminates.

Here's the part in question:

You must be registered for see images attach

(Did you catch the part about the only way to turn the lamp off? Post fix you have to push the brake pedal hard enough to develop ~450 PSI to recenter everything.)

****

The short answer to your question is to go ahead & give everything a thorough bleeding.
Give your brake system the gift of clean brake fluid everywhere. And after all this bleeding,
assuming the brake pedal firms up, a final firm pedal depression should extinguish the
brake light for you. (Assuming it's the Combination Valve that is providing the ground for this bulb.)

NOTE: If it's not the Combination Valve, but instead it's the ABS box, then that's a different
story. If you don't already have a set of GM Factory Service Manuals by your side, then
you can download the .pdf files that I just used to post these pages. ('88+ GM FSM links)

But given your recently opening up the rear brakes the probability is that your
Combination Valve is where the constant brake warning light is coming from.

Give this a try and let us know how it turns out.

Best of luck with your brakes --

I wonder with ur manuals is there a diagram of witch wire is witch on the abs module?

 

[Road Trip]

See if these wire colors and pins match up with what you have:

You must be registered for see images attach

If you are still chasing the brake warning staying on, the tan/white wire to Pin H is your focus.

NOTE: See attached for the 2nd page of this connector's wiring diagram.