electronic/wiring questions:

[rookie_LC2]

Hi again, i posted earlier about charging problems with my new '87 T.
Bad alternator. Replaced.

I had a chance to look at the car this afternoon, there is still one more problem with it. The brake lights do not function. We checked the fuses, the grounds, bulbs, misc. wiring. Everything seems to check out. Went out to autozone to pick up a brake light switch, replaced that. No dice. Possibly the switch is not getting any power? We didn't have a voltmeter...

Is there an additional trigger on the master cylinder for the brake lights? I'm running out of ideas.



One more thing: when we replaced the brake light switch, there was one plug under the dash that was not connected to anything; covered in electrical tape. I removed the tape and saw that there was a bare wire jammed into the socket (not a paperclip) Does anybody have any idea what this cable is for?
-Its a loose cable, the plug is clear plastic.


thanks in advance for the help!

 

[salvageV6]

Power comes from the Stop Hazard fuse. Check it first. 20 ampere fuse and hot at all times.

Does the third brake light on the rear deck work?

Do the hazard flashers work?

Use a test lamp and check for power on the orange wire for the brake light switch should always have power on it.

Then check the white wire with the pedal pushed switch activated it should get power.

White wire goes to a connector C104 on the right side of the steering column, sometimes it gets pinched or pulled out and you lose the brake lights. But you should still have power at the switch output if this is the case.

 

[topfuel]

White wire goes to a connector C104 on the right side of the steering column, sometimes it gets pinched or pulled out and you lose the brake lights. But you should still have power at the switch output if this is the case. [/B][/QUOTE]

I found my white wire at C104 melted and burned causing my brake lights to fail. Cut out and replaced the bad section to fix it.
Good call salvage