1989 Camry LE brake wiring fault

[89Camry89]

Does anyone know the path of the Green w/Red wire that feeds the brake light?

Recently the rear high mount brake light (3rd brake light on the deck in the window) stopped illuminating. The light was ok, and I found there was no voltage at the terminals when the pedal was pressed. I have continuity to ground. The other rear brake lights illuminate just as they should.

I tried to find a broken spot in the wire but I am having the darndest time finding exactly where it goes once the bundle enters the loom in the side of the car.

I've ruled out it goes forward (unless there is a splice inside the loom that I missed). Also, no Green w/Red emerges under the dash.

Presuming it goes rearward into the trunk, there are 2 (or 3) forks it could follow. Alternately it could splice inside the loom and change colors, thereby eluding me. Both of those forks have Green w/Red wires coming out of them. One fork's wire goes into the light failure sensor. The other fork has two wires - one for the left side brake and another for the right.

Do you know where to find this wire?

Thank you.

[hairball]

I'm looking at my wiring diagram and I'll assume you have the brake light failure sensor in the trunk. There is a different diagram indication for with/without. If you're not sure what I'm talking about, open your trunk and pull back the liner from the driver's side trunk wall and see if you see a yellow box. Let me know.

I'm going to ASSUME it has the sensor (yellow box):

That green wire with red stripe goes from the 3rd brake light to the right brake light, then over to the left brake light, then to the yellow box (sensor).

About the only thing I can suggest is to test the box. Here is the procedure. Very simple.

[89Camry89]

I do have the tail light sensor in the trunk.

The power antenna stuff is gone and its plug dangles. I removed that 10 years ago.


I will try that test procedure tomorrow - thanks. Until then, here is a rough sketch of what I found as I studied the wires.

I looked in the back of a Haynes book I have. Although as a diagram it gives the correct wire colors, it shows nothing about the physical path of the wires.

I checked at the tail lights to see if there was a splice or a wire was doubled up on a terminal to go back up and supply the high mount light, but I failed to locate it.

I am able to get at most of, but not all of the loom. There is a section that I can see and touch a little bit, but don't think I could get it open.

[89Camry89]

Update: It's fixed.

I went through the test procedure as per the diagram and all of the results were as expected.

Not feeling fully convinced, I installed a jumper wire from the high mount light green w/red wire and tested continuity between that and the left tail light green w/red wire. Beep, there was continuity. I also confirmed that ground seemed good, therefore it didn't make sense that it wasn't lighting.

After going back to the high mount light fixture and doing more testing, I learned that the wires feeding the fixture was all good. The problem was in the socket itself. There was power at the wire and at the brass ring that connects to the socket shell. This may be a crimp connection. In any event, the socket where the bulb casing touches the socket was not getting a path to ground.

The reason I missed all of this before was that when I first probed the fixture, I probed between the center pin of the socket and the outer shell of the socket - right where the bulb plugs in. When I read zero volts, I interpreted that to mean I had a bad wire. (I recently had a broken wire to the trunk light bulb in the same general area).

Without expecting this problem, I did not unplug the fixture and probe the wires at the plug. If I had done that first, I could have noticed the discrepancy between voltage at the wire and no voltage at the socket just a half inch farther down the circuit.

My solution was the solder a jumper wire from the wire, through the plastic fixture, and onto the outside of the light bulb casing on the socket.

I'm a bit upset with myself for not catching this before I put about 5 hours into tracking this down. I need to reassemble about 60% of the interior of the car now.

Here are photos:







I appreciate your help.



Next up will be round 2 troubleshooting the power door lock on the driver side to figure why it can lock all the doors, but unlocks none. I think I will need to sleep first.

[Darwin686]

Originally Posted by 89Camry89

Update: It's fixed.

I went through the test procedure as per the diagram and all of the results were as expected.

Not feeling fully convinced, I installed a jumper wire from the high mount light green w/red wire and tested continuity between that and the left tail light green w/red wire. Beep, there was continuity. I also confirmed that ground seemed good, therefore it didn't make sense that it wasn't lighting.

After going back to the high mount light fixture and doing more testing, I learned that the wires feeding the fixture was all good. The problem was in the socket itself. There was power at the wire and at the brass ring that connects to the socket shell. This may be a crimp connection. In any event, the socket where the bulb casing touches the socket was not getting a path to ground.

The reason I missed all of this before was that when I first probed the fixture, I probed between the center pin of the socket and the outer shell of the socket - right where the bulb plugs in. When I read zero volts, I interpreted that to mean I had a bad wire. (I recently had a broken wire to the trunk light bulb in the same general area).

Without expecting this problem, I did not unplug the fixture and probe the wires at the plug. If I had done that first, I could have noticed the discrepancy between voltage at the wire and no voltage at the socket just a half inch farther down the circuit.

My solution was the solder a jumper wire from the wire, through the plastic fixture, and onto the outside of the light bulb casing on the socket.

I'm a bit upset with myself for not catching this before I put about 5 hours into tracking this down. I need to reassemble about 60% of the interior of the car now.

Here are photos:







I appreciate your help.



Next up will be round 2 troubleshooting the power door lock on the driver side to figure why it can lock all the doors, but unlocks none. I think I will need to sleep first.

Round Two. DING goes the bell.

Power door which problems are generally three thing.

1. Bad switch.
2. Bad contact with the wiring harness and the switch terminal a little dielectric grease will fix this.
3. Broken wire.

Good luck.