Hi folks,

Got a 1990 LX, 117k on it, with a brake light issue and no other past electrical problems. I've read the other posts on this issue from RedBull-1 and others and need a bit of help still.

The passanger side and center (rear window) brake lights are out. The turn signals and warning lights work on both sides. The driver side brake light works. The brake light indicator is on on the dash (and is always on now when I start the car).

I checked the passenger side bulb. It was fine. I cleaned up the little bit of rust there was around the connections and replaced the bulb. Nothing. No water in the plastic cases. I had a friend (with the car on) hold down the brake pedal and I jiggled the wires looking for a loose connection. Nothing doing.

I'm not real skilled at electrical and since the center and passenger brake lights were out, I figured it was most likely the failure sensor (based on other posts). However, I replaced it (with a factory part) and still they are not working.

I took a multimeter to the brakelights. On the driver side (which is working) I got a normal 12V reading. On the passenger side I'm getting a reading of .0029 (with the brake pedal depressed).

I don't see any visible corrosion on any bulbs or connectors, and I'm not sure how I should approach this now to troubleshoot.

Does anyone have an idea of what to do next? Would you say I should try to clean the connectors on the failure sensor pin or is the low voltage reading a sign of something else being wrong?

Thanks, really appreciate y'alls help.

 

Repeat the voltage test on the passenger side, but touch the black volt meter lead to a bare metal bolt on the body. Let us know what voltage you read.

 

Thanks for the help PA.
I repeated the voltage test on the passenger side, with the ground to bare bolt. I got a reading of .0023 (this is with the brake pedal depressed).

 

Is this car a hatch back five door.?? If so check the wires that go through to hatch hinge area they could possibly be broken. as the hatch goes up and down they eventually damage the wires

 

Hi Kwakers, not a hatchback. its an LX.

 

We're us the high level centre brake light fitted ?

 

Thanks for the help PA.
I repeated the voltage test on the passenger side, with the ground to bare bolt. I got a reading of .0023 (this is with the brake pedal depressed).

 

The 0.0023V reading is essentially zero volts. I don't have a good shop manual for the 90-93 accords. I think there was a brake light failure sensor on some of those accords. It is part 28/29 in the diagram below.

There should be a green/white wire that provides it power when you hit the brake pedal. Use your volt meter to test like before. Also try this test on the same color wire on the driver's side tail light. Both wires should have 12V when you push the brake pedal and not have 12 when not pushing the brake pedal.

 

Thanks for walking me through this, PA.

I'm getting a solid 12V on the DS, but poking the green wire coming into the brake light on the PS I still get nothing.

Because the center and PS brake lights are out, I actually replaced the failure sensor already (the 1990 has one), hoping that would be an easy fix (found a new one on ebay for $15). It didn't fix the problem.

Is there anything you'd suggest as a next step for troubleshooting? I've got a Chalmers for 89-92 Prelude/Accord.

 

I meant to say test for power on the green/white wire going to the failure sensor on both the driver's and passenger side tail light. Not working with a great wiring diagram, so verify the grn/wht wire switches to power when the brake pedal is pushed. Then try on the passenger side failure sensor.