The brake lights come on with the headlights, but do not get brighter when I hit the brake pedal. I checked the bulbs and they are good. I checked the fuses and they are good (there are only two that I know of: TAIL and STOP, in the driver side kick panel.

Is there a switch that sends the signal that could be faulty? I'm at a major loss here. It is so dangerous to be driving at night and have others not know when you're slowing down. Thanks.

 

I just tested the plug at the light and I do not get voltage when the brake pedal is engaged. Shouldn't be a break in the wire because both sides do not light up. Is there perhaps a relay inline somewhere?

Blinker - green w/ black stripe
Ground - white w/ black stripe
Brake (low) - solid green
Brake (high) - green w/ white stripe

 

There's a stoplight switch for the brake pedal, id check that out if the fuses are ok.

 

Check the switch on the brake pedal. One side should have 12 volts all the time and the other side should go to 12 volts when you press on the pedal.

 

Okay. The switch has a 4pin connector. I have the FSM for a 95 runner but the pin config is different than what I have. The manual shows...
_ _
_ _

and says to check for continuity as...

switch pin free (pedal depressed) - terminals 1 and 2 continuity
switch pin pushed in (pedal released) - terminals 3 and 4 continuity

My switch looks like...
_

| | |

I get continuity between the top horizontal and middle vertical terminals without the switch depressed.

I also get continuity between the left and right vertical terminals with the switch depressed.

Without the right diagram, I cannot work this out. I'm not sure how to check for voltage when this is all plugged in, except that the pin terminal at the tail light does not get voltage when the brake pedal is depressed. Anyone know where I can get the right diagram? I'm gonna keep searching online. Best thing is that the switch does not have a part# stamped on it anywhere.

 

This keeps getting better and better. I found a manual for an '85 that shows the same config of the switch I have. I tested for continuity as the manual states and everything checks out. So now I have to track down a short in the wire. Why is it that it's never the easily replaceable part that goes wrong?

 

should the plug that connects to the switch have 12 volts?

 

Okay. The switch should be getting 12V. In my case, it is not. Woohoo...I found the problem. So I check the fuse. The fuse is good. I did a visual inspection and tested it with the meter for resistance >> 0 omhs >> the fuse is good. I replace the fuse and test for voltage. I get 12V on the IN side but nothing on the OUT side. ??? But the fuse is good. I remove the fuse and replace it with a jumper wire. The switch gets 12V and the stop lights come on. Sweet. I put the fuse back in and nothing. WTF.

The million dollar question is why does the jumper wire work and fuse does not? I didn't see any corrosion and the fuse fits tightly into the holder.

 

maybe just a funky fuse.....did you try a different fuse of the same amperage?

 

must be a jeep fuse and doesn't wanna work in a toyota.
seriously though, try a different fuse.

 

Damn jeep fuses. I tried 4 fuses from different packs, all the same amperage. I really don't wanna hafta pull the fuse block out to inspect either, but my options are fading at this point.