I turned the ignition on today and the brake indicator light in the gauge cluster wont turn off. Ive checked my brake fluid and tried bypassing both the brake fluid level switch and the e brake switch and it wont turn off. When I hit the e brake switch i can see the light dim a just a little bit. Is there anything else that is connected to this light? Only thing eletrical ive messed with are the 2 wires coming off the seat belt latch on the drivers side. that wouldnt be tied into the brake light would it? Ive tried touching them together and grouding them but that doesnt work.

 

parking brake

 

Ive tried messing with the parking brake like i said in my original post "e brake."Could it not be grounding maybe? I pulled the cluster off and there is some kinda of diode or somthing that it tied into the brake light on the cluster a couple inches away.

 

Fill the fluid, trust me its low.

 

its filled and like i said. I BYPASSED BOTH THE PARKING BRAKE AND BRAKE FLUID LEVEL SWITCH!! In my haynes manual the wiring digram shows the green wire with white stripe goes to a brake fluid switch, parking brake switch and also a vaccum switch. Anyone have any idea what this vaccum switch might be?

 

Yea you sure you bypassed them? I'm not being a jerk but the fluid tank needs to be filled tot he brim!

 

Yes its full BUT i just found somthing new. My brake light turns off when the charge light turns off(after i start motor off course). while its running with the charge light off the brake light works as it should. There is a diode that runs between the two lights and im thinking thats the problem. i guess i could live with it but if it could potentially be a problem ide rather fix it now.

 

Check your charging system. My 89 did that when the alternator went out. I didn't think to check the voltage or charging because I was worried about the brake light...then as I left for a roadtrip I watched my lights dim and stereo go out as I barely made it off the highway. Two years later, the "lifetime warranty" alternator went out again, but I knew that was the case when the brake light came on and I made it to the auto parts store so i could trade it out in their parking lot. i don't know why it does this, but its worth checking.

 

My charging system working great. I turned on my headlights and heater fan full blast and barely dropped voltage. I dont plan on making any long trips with my truck anytime soon so if somthing does fail it wont be a big deal. Im gonna check my regulator grounds and stuff.

 

I worked on my brakes today and let the fluid drop to 1" of the bottom while bleeding them but not any lower. I added fluidwhen it got low and it is now at the max level reading. When I turned on the engine the red dash light was on. To determine if it was caused by the switch on the reservior by disconnecting it. The light went out every time. I did the "tv thing" and tapped the reservior on the side to see if something was stuck by my going to low initially. The light went out and I thought I had everything resolved. Well now the light comes on when ever I accelerate and goes off when I brake hard. Now I am sure it is the reservior. Has anyone ever taken the reservior off and clean it out the correct the switch issue. Am I thinking this out correctly about removing the wires on the side of the reservior making sure the problem is in the reservior level switch?

I can't believe I have this and another light issue, I only have 191,000 miles on my 97 T100.

 

did you check your brake light fluid and your charging light fluid? if its low then that could be a reason its comin on.

 

Can anyone describe what is actually in the reservior. Is there a simple float switch or what. My wiring diagram seems to show a variable type normally open switch. Any insight would be appreciated.

 

it's a simple float. Taking a very small hammer (4oz) and tapping the reservoir usually makes the float come up to the top.

There are 3 things that turn the brake warning light on.
1. low brake fluid
2. e-brake handle switch
3. charge light circuit

HTH.

 

You may have already done this but mine stays on unless I push the brake all the way in

 

Mine was just turning on with the charge light when the ignition was on and engine wasn't running. I checked a few friends pickups and they did that same thing.

 

Mine had a problem with the parking brake switch, the little tab that actuates the switch was missing/broken off when I got it, I ended up disconnecting the lead to the switch, no problem now except occasionally I forget and drive off with the brake on [D'OH!], but you said you by-passed the switch so that should'nt be it... still you might try unplugging the switch just to see... other then that it might be a short somewhere in the wiring/cluster if it is not the float switch thingy...
Sorry I can't be more help... aviator

 

Stumbled onto this thread while checking other problems with dash brake indicator light. Mine started coming on when I first start driving but sometimes goes out when i brake. Hey deserttoy84, if your saying you bypassed the park and fluid level switches, that means you connected the wires together? if so that will make the light come on. Simply unplugging the fluid level switch and park brake switch is enough to elliminate them from the system.
My park brake switch is fine. However the fluid level is all the way up too. I plan to check the hall effect switch in the fluid level float cap. I will post results.

 

like i said before... I ended up not having any problems. It just turns on whenever the charge light is on so its more noticeable. Mine goes out after i start the engine and brake is off

 

try tigtening the ebrake cable and that should turn it off