There probably is a short in the circuit (e.g., wire touching other wire, etc.).

If you have a voltmeter you can do some testing.

1. At the driver's side fuse box, with the headlight switch turned off, check if there is power at the Red/Blk wire at terminal no. 1 of the connector in the attached photo. You can backprobe that terminal.

Backprobing is either using a backprobe set or using a thin needle or something and making contact with the metal terminal of the connector without piercing the wire in the back of the still connected connector. Care must be taken to ensure that the wiring does not get damaged. You can use something like a T pin, available at Walmrt, etc., and backprobe. These pictures are just to give a picture of the concept of backprobing without piercing any wires.

https://www.hondaaccordforum.com/foru...%5D-t-pins-jpg

https://www.hondaaccordforum.com/foru...back-probe-jpg

There should be no power on that wire with the headlight switch turned off.

Report your findings.


2. If there was no power at that Red/Blk wire, then the short probably exist further down the circuit. Some other wire may be supplying power to the Red/Blk wires to the tail lights.

On your coupe, visually check the wiring and connector at Connector C554, located at the left side of the trunk.

Thanks redbull. That's a good starting point for me. We're supposed to be getting some winter weather again over the next couple of days so I'll check into it when we get another break. At least I have a direction to go now. I hope it's something simple.

Ok, the red/black wire inside the fuse panel does not have power when the switch is off. It does when the switch is turned on.

The plug in the trunk looks fine. Nothing appears to be shorted or anything. Which wires should have power at that plug?

If I unplug the tail light failure sensor the lights go out. There is power to it.

What else should I check or test?

There have been problems with water getting into the trunk light panel and the right side tail light housing. I'm thinking this may have caused a short. We had a lot of water at one time in the right side housing which blew the light out. We got the water out and replaced the bulb and everything worked fine. This is a problem that just happened out of the blue one day.

None of those wires should have power with the ignition off, headlights turned off, brake pedal not depressed, car not in reverse, etc.

See which wire at the connector to the brake light failure sensor has power with everything off.

Well, I have power at #1, WHT/BLK - Brake Switch Input.
All the others are dead.

If you unplug the brake switch connector, is there still power at the Wht/Blk wire?

Also your initial post in this thread indicated it was not the brake lights on; but, the tail light, is this still the case?

Ok. Well, it turns out that I was mistaken. It is the brake lights that were on. I didn't realize that they also lit up in the trunk light panel. I thought those were only running lights in there and the brake lights were the ones on the corners.

Anyway, when I crawled under to unplug the switch I noticed the plunger wasn't hitting on anything. The little plastic disk broke off and was laying on the floor. I put it up to where it pushed the plunger in and the lights "miraculously" went out. Imagine that. It didn't help matters that the 3rd brake light bulb is burned out so it wasn't coming on to show it was the brake lights.

Thanks for all your help. Sorry it was such a simple problem. Well, not really sorry because it's such an easy fix but sorry to bother you with all of this over something simple.

It was no bother. I was giving test steps to narrow down the cause. I'm glad you resolved it. :)

Yeah, I just feel like an idiot now. It was daylight when the problem happened so it was kind of hard to tell they were brighter than running lights. That along with the 3rd light not working and me thinking the center lights were just running lights all lead up to my mistaken deduction.

I really do appreciate all your help though. Thanks.

Now I just have to figure out where the water gets into the right tail light. I know where it's getting in on the trunk piece. There's no gasket where the trunk key cylinder is. I'm going to have to try silicone or something to seal it.