Right side taillight not working?

Yes, I have power at both fuses at that location, when I switch on the park lights, I can also hear the relay clicking, I have replaced both of them with new just to make sure.

It’s the right side that is not working, passenger side of truck, you always go by when you are sitting in vehicle correct. Just want to make sure we are on the same page.

Do you mean gray and brown at the taillight? Should I check it at the bulb socket?

No power at marker lamp when switch is on.

No power at marker light socket.

Okay, the power block in the back by spare tire, I have changed, so it’s going to be from that block to the front of the truck, it’s not going to be easy but I’ll get under it on drivers side and look for some kind of damage in any harnesses I can see. Thank you

I have a question, if the power from the relay and both fuses go to the taillights, does that power also go to the license plate light sockets, both of them bulbs have power. That would tell me that the power supply from the fuses is making its way to the power block or at least to the back of the truck. I guess I’ll have to peel back some more wire covering to see if the damage is at that location near the power block.

Hi, I removed the power block, disconnected all the plugs, used a test light checked the power at the harness coming from the front of the truck, has full power, left taillight at the block with power harness plugged back in, has full power at the power block, the right hand tail light only has about half power when tested with the test light at the block, it’s the only plug socket in the block that doesn’t have full power. Would this indicate bad ground coming from front of truck, headlight switch, fuse panel, battery ground to firewall or block. I have removed three grounds cleaned and reconnected at back of truck, each side of frame on the front of truck.

Nothing has changed, testing at end of taillight harness at bulb locations, side marker no power. At power block with taillight harness removed two very weak signals dim light, every other plug has full power.

I would agree with you, but the block is new. I replaced it and the right taillight harness at the same time, about two weeks ago. Unless it is screwed as well, I just can’t get my head around it being toast like the old one.

I turn on the park lights, ground out the test light to the frame and find the power in that harness coming to the power block, then I take the grounding side of the test light and touch every one of the other pins and I get a light except one. I think I’m still missing something.

I should have found the ground and touched the power to see if I had a light, I think I’m not getting a good ground in that harness from the front of the truck. I’m running out of ideas.

Hi guys, I was wrong, I put back in the old harness, cut the ground and added my own, plugged it back into power block, turned on park lights didn’t work. Then I added a power wire, cut the power lead brown and added power from my trailer plug to the harness, turned on the park lights and now have taillights. I don’t know what changed, I tested what I thought was the power coming into the power block, one pin has full power, the power block is new, but I guess it could be faulty, are there two powers coming from the fuse panel to the back, when I tested power block I had full power and a weak power in the harness and also the socket when I plug in the front power harness to the power block.