I have an 03 Honda Accord EX V6 Sedan. The tail lights are completed out but the brake lights work. The turn signal also works but some reason the parking lights are gone. I checked all the applicable fuses but none are blown. I also check the bulbs but they are good. I suspect that the rear wiring hardness lost the ground connection. Does anyone know where the rear wiring hardness ground location is?

 

I don't know your specific model but, it's usually under the trunk lip behind the carpet.

 

Is it in the back of the trunk or on the trunk lid? I did want to take out all the carpet to look for it. Thanks.

 

Open the trunk, look down. The front wall of the rear bumper- if that makes sense.

 

Thanks, it is actually on the left side of the back of the trunk (front of bumper as you said). However, the ground is good and tight, not the problem. Now I am looking for the second ground bolt in the front of the trunk. Coincidentally, I noticed that both rear door lights are out too.

 

Those are reflectors on the rear doors. Do the front parking lights work? Do the tag lights work?

Fuse 4 (15a) in the underhood fuse box labeled 'small light' is for the taillights.

 

I think I checked every fuses under the hood and inside the cabin and none are open. I thought I check that specific fuse #4 as well as I read from another forum. The front parking light works fine and the four way hazard works too (including the rear markers). When I lock the doors, only the front markers blink and not the rears. All the tail lights and the licensing plate are out but the brake lights work fine. That lead me to believe that there is a grounding issue with the tail light circuit or relay problem. I ordered the relay to see if that fix the problem. If that does not work, I think I will replace the multi way switch.

 

I agree, relay then combo switch. Personally, I would have just checked the relay instead of waiting for one to be ordered. You have more patience than me.