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Brake lights

Sketchysedan

New member
Joined
Feb 20, 2019
I recently bought an ?87 240 wagon. When I got it, only the high mount brake light worked, but that recently stopped working. I suspect it is the wiring in the hinges fraying for that one, but neither of the other brake lights work. I have verified voltage at the fuse board and pedal sensor, verified that the pedal sensor works, and swapped out for a known good bulb failure sensor from my ?87 sedan. Brake lights are still not working, I am getting no voltage at the wire for brake lights in the rear of the car and I do not get a bulb failure warning light on the dash. Cruise control also stopped working the same day the third brake light stopped working, unsure if that could be related or not.
 
Yeah I still have the relay. Is there a way to actually check it? And yes, I was getting power on both sides of the fuse
 
You can test the bulb out sensor relay by using a test light. It just has various circuits connected to it with in and out locations. So when you hit the brake pedal. You should get voltage passing through from in to out for the brake lights. It would light the test light.

PS Open your hatch and look at the hinges. If you see wiring that is broken and split. Then you need the hinge wiring harness replaced or repaired. .
 
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Yeah all the wiring is cracked or broken in the hinges, the rear wiper and rear window defrost do not work, and I suspect that is why the 3rd brake light stopped. That shouldn?t have anything to do with the outer brake lights on the body not working right?
 
Yeah all the wiring is cracked or broken in the hinges, the rear wiper and rear window defrost do not work, and I suspect that is why the 3rd brake light stopped. That shouldn?t have anything to do with the outer brake lights on the body not working right?

No - IF it is not shorting to ground and blowing the brake light fuse. I suspect you would have noticed though.
 
Yeah brake light fuse has been intact this whole time. I?ll try and check that bulb failure warning relay later tonight
 
Are all other lights working? (turn signals, reverse lights, tail/running lights, single rear fog)

A couple other things you can check:

You can remove the spade connectors from the brake switch and short them together (careful not to short to ground on the nearby metal bracing - will pop fuse quickly!). Then check for voltage back at taillight assembly wires.
You can pull back the headliner in the rear corners and check for voltage to 3rd brake light - would at least indicate some wiring is good that far back.
 
Yes, all other lights are working. The only thing is I think it has the wrong headlight relay as when I turn on the parking lights, the headlights come on. But yes, everything else works. And I tested the brake lamp switch with a multimeter, it opens/closes the circuit as it should. I have already tried connecting the two wires normally plugged into the switch together and still no brake lights or voltage. What?s especially weird is I am pretty sure I had the right rear brake light working intermittently.
 
Definitely need to trace power with a test light. Check the input/output terminals on the bulb out relay. How do the bulbs look? Very often the gaskets on the lights leak and the water causes the bulbs to fail.
 
Just checked out bulb failure relay. I?m getting 12v out of 4 of the pins with the brake pedal pressed down, and still no bulb out light on the dash. Where does the harness run in the car? Does it go straight from the bulb failure relay to the bulbs or does it pass through anywhere else I need to check?
 
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