Turn signal vs trailer wiring?

So my left turn signal it stuck on. I found this thread. Symptoms are about the same and the issue was traced to the trailer wiring harness. I also had an issue where I tried to rent a uhaul motorcycle trailer and couldn't because my trailer wiring is non-functional.

Sounds to me like its time to rebuild my trailer wiring harness.

Any suggestions or tips? 2008 Tacoma pre-runner w/ four banger.

 

You can test it with a voltmeter. It should read 12v on each of the lead for the turn signal and brake lights when actuated/applied. That should tell you if the controller is working on the truck end. For the trailer end, you can use a 12v power source and put a lead on the ground and then each of the other contacts to see if they light up.

 

Thanks Nessal, I'll throw a spare battery to charge and dust off my multimeter.

 

Do you have a 4 wire or 7 wire? You posted in the 1st gen forum so I assume you will have a 4 wire but you said your Tacoma is a 2008 and I believe those are 7 wire. They sell this item to test your wiring on the rig side as well. I have never used it since I have a multimeter but this takes the guess work out. I had some issues with my trailer as well and it turned out to be the controller after going through all of the test procedure. Was a real head scratcher since my issue was intermittent.

$12 NEWSUN® 7 Pin Trailer Plug Tester with LED Light, 7 Way Trailer Light Tester, Round RV Blade Electric Wiring Tester, 7-Way Trailer Light Circuit Connector Tester for Truck, Trailer, Rvs, Plug & Play

https://www.amazon.com/NEW-SUN-Trai...2789945&mcid=6be5dfc16b363ef7bf2c01164de7e59a

 

4 wire on mine. Oh, man that Harbor Freight one for 4$ is gonna help. I didn't even know those existed. Tha!