Tail lights not working on one side

[lesteph1520]

We have a 2016 Cedar Creek 33IK. The passenger rear tail lights do not work when braking or signaling a right turn. We replaced the two oval lights but still not working. BUT, when we turned on the truck headlights, the lights worked. All other lights work all the time. Any ideas what to do next?

[LittleBill]

Originally Posted by lesteph1520

We have a 2016 Cedar Creek 33IK. The passenger rear tail lights do not work when braking or signaling a right turn. We replaced the two oval lights but still not working. BUT, when we turned on the truck headlights, the lights worked. All other lights work all the time. Any ideas what to do next?

You don't mention whether or not the truck tail/brake/turn signal lights work or not. If they don't then you may have a bad turn signal relay. Does the 5er's tail light work at all? If it is only one bulb that does both tail light/brake light/turn signal the filament in the bulb for the brake light/turn signal could be bad. Try swapping the bulbs out with the driver side and see if that works. If the passenger bulb works/doesn't work on the driver side then you have somewhere to start.

The connection/wiring to the passenger side could be corroded/loose at the light or somewhere in the wiring harness. Lots of possibilities as to the specific problem, you will have to investigate, back track and eliminate them one by one.

Good luck and be safe -

[lesteph1520]

We got it solved!! It turns out there are fuses in the truck under the hood that are for the trailer lights...who knew?! (One service person we called said if all the other lights worked, it wasn't a fuse....so we didn't pursue that line anymore.) We replaced a small red 10 amp fuse under the truck hood and voila, we had turn/brake lights on the trailer. (The truck lights always did work.) We are very happy campers now.

[5picker]

Originally Posted by lesteph1520

We got it solved!! It turns out there are fuses in the truck under the hood that are for the trailer lights...who knew?! (One service person we called said if all the other lights worked, it wasn't a fuse....so we didn't pursue that line anymore.) We replaced a small red 10 amp fuse under the truck hood and voila, we had turn/brake lights on the trailer. (The truck lights always did work.) We are very happy campers now.

I can't speak for other manufacturers but Ford has been using separate fuses for the 7 pin connections for decades.

[Mr. Dan]

Originally Posted by lesteph1520

We got it solved!! It turns out there are fuses in the truck under the hood that are for the trailer lights...who knew?! (One service person we called said if all the other lights worked, it wasn't a fuse....so we didn't pursue that line anymore.) We replaced a small red 10 amp fuse under the truck hood and voila, we had turn/brake lights on the trailer. (The truck lights always did work.) We are very happy campers now.

Who knew? I did but I didn't get a look at your original post or I would have helped.
My GMC blew the same red 10a fuse for one of trailer's tail lights.

[jbflag21ds]

Originally Posted by Mr. Dan

Who knew? I did but I didn't get a look at your original post or I would have helped.
My GMC blew the same red 10a fuse for one of trailer's tail lights.

I only knew because I found out the same way the OP did, just a few months ago.

[LittleBill]

Originally Posted by lesteph1520

We got it solved!! It turns out there are fuses in the truck under the hood that are for the trailer lights...who knew?! (One service person we called said if all the other lights worked, it wasn't a fuse....so we didn't pursue that line anymore.) We replaced a small red 10 amp fuse under the truck hood and voila, we had turn/brake lights on the trailer. (The truck lights always did work.) We are very happy campers now.

I had forgotten that a fuse might have blown. On my previous TV I had the 30A fuse that sends power to your unit blow. The service guys at the RV dealership helped me find out that it was blown when I couldn't operate the RV's jacks when connected to the TV. It happened a couple of times where I ended up by buying a pack of 10 on Amazon.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Be safe -

[lesptr]

I’m glad you found the problem.
I had the same problem.
It turned out to be the pigtail that connected to the 7pin on the bumper to the 7 pin connector in the bed. I replaced that wiring harness and have had no problems since. (I also replaced one tail light assembly on the 5r, which solved the problem for about an hour). Maybe I should up my trouble shooting skills.

[lesteph1520]

We also have a GMC. Do you know WHY it blew?

[The Newsoms]

Our blows the fuse every time we tow.