No Trailer Running Lights

When I connect my travel trailer to the Tacoma, I get brake, and turn signals but no running lights. All my lights on the the truck work fine. I have connected a friends Titan to the trailer and all the trailer lights work. Recently I added a P3 brake controller and I relocated the trailer plug to my bumper. I checked the fuses by the battery and they all are fine. I rechecked my wiring and it is correct. I am running out of ideas. Are there any fuses I am missing? Thank you for your help!

 

Either the bulbs are toast, you have a wire fault, or no ground.
Check for 12 vdc at the bulb.

 

There are no problems with the trailer lights, it is a problem with the truck. Are there inline fuses on the second gen trucks?

 

Try the other fuse box. It is behind the pocket door above the ebrake or the clutch like mine.

 

just checked, all the fuses in the pocket under the steering wheel are ok...

 

Ok, misread your post.

Do you have 12v on the running light's pin, and ground at the truck's plug?

 

Ok lets see we have tail lights on the truck but not the trail. So if you have a test light check the inside of the plug just ground the tester and start touching the prongs if you dont have power try the wires behind it if you have power you will have to take apart the plug and check the wires for connection sometimes they come loose. if the wire does work just keep tacking back until you get power.

make sure you have a ground by testing the turn lights

this would be easier by phone

 

Relay under hood?????I just installed a wire harness on my pontiac and had to install 2 fuses and 2 relays under hood

 

I know there is a relay in the fuse box behind the battery relating to the trailer, how do I test if this is ok? I do not have a test lamp or a voltmeter, but may be able to get one tomorrow. I know the wires in the trailer plug are installed correctly and not loose b/c I tore them apart tonight.

 

Also, the trailer's turn signals and flashers work as well as brake lights so I don't think it is a ground problem at the plug.

 

is it factory or after market

 

swap relays with another identical relay.

 

Factory tow package, Ill go out and swap a relay...

 

Well not sure what else to say but its in either fuses, relays, or just as little as bushing the prongs a little to make sure you have good contact.

Good Luck

 

the 12v towing relay in the box under the hood is ok. I swapped it out and still have no running lights on the trailer

 

I hate electrical problems... I am not sure what else to do. I will try the voltmeter tomorrow and if I still can't find it, i guess i will let the shop take a look. I really need this fixed so I can tow the trailer for the 4th of July.

 

I've been having this same problem since I got my 09. It's got the factory tow package and I get turn/brake but no run lights. I've checked all the fuses and I'm ready to go nuts. The dealership told me that everything checked out ok. I've just not been towing my trailer after dark. It's a major inconvenience. I'll be sub'd to hopefully find a solution.

Is your trailer a 4-flat plug?

 

No my trailer has brakes and uses the rv 7 plug.

 

I'm jumpin on this thread. All lights on my trailer work except the running lights. Turn signals work, brake lights work, hazards work, and even trailer brake works. Its not my trailer because it was found at Uhaul trying to rent one of theirs.

I have a '09 Sport with factor towing package (7 pin connector). Help.

 

Does the pin that is for running lights, truck side, show 12v on a DVM?

If you apply 12v directly (from another source) to the trailer side pin, do the lights work?

If yes to both, the problem is in the connection, likely on the trailer side.

If the answer to one is no, then that has to be resolved first, then retested, as there could be multiple issues.