Brake lights mystery

[festyxfi]

Group,

The 88LX I'm working on has a mysterious problem with the brake lights. I've replaced the fuse, brake sensor under the dash (at base of pedal) all the bulbs, they still won't work. The rest of the lights work properly. Advice on what to look at next?

Thanks,
Brenton

[festyxfi]

Seriously. no ideas anyone?

[sam.1956]

I've seen 2 cars (mine was one) where the wire was broken at the place where it comes out of the car & goes into the hatch. The rubber boot wire cover/protector is a serious pain to remove, and the wires had been pinched and/or flexed so much over the years by the opening & closing of the hatch that they finally just broke in half.

I found enough slack in the wire (inside the hatch) to pull it out a little & make a good splice. I then put some plastic split loom over the wires & then wrapped it in electrical tape for some degree of abrasion protection. So far, so good!

[hotfordcat]

sounds like a break in the wiring. Start with a test light at the rear lights, have someone step on the brake pedal and see if the test light lights up. If not, move further down the harness. I have a test light that you hook over the wiring and push the probe into the wire, which helps quite a bit.

[festyxfi]

good ideas both, thanks! Q: when talking about the hatch wiring, is that to the 3rd hatch light? Would that short all the brake lights?

[sam.1956]

Yes, the 3rd brake lite does go thru there, as does the rear defroster (if so optioned) and the rear wiper (if so optioned) and of course the tag lites. You could unplug the 3rd brake lite harness at the hatch and see if that affects you other lites.

Then too, the wiring harness out of the firewall to the back end of the car is routed along the floor in a few places. Ample opportunity for breaks, pinches, severed wires.

If none of this helps, it's time to break out the old schematic & grab your favorite Fluke DMM for some Electro-Gremlin Exorcising... yee-haw.