Originally Posted by jjsask
Does your left turn signal light work on the truck? If so you likely have a problem with your taillight converter and/or its associated wiring. If you have a Toyota OEM converter it could be installed in a number of places, I know it is in the compartment below the rear drivers side jump seat on XtraCabs but its location is different for regular and double cabs.
If you have an aftermarket converter it will be either tucked in behind one of your taillights or tied up behind the back bumper near your 7 pin connector. If the converter is dead you will need to replace it, the only thing you can really check for is to find the wire that goes from your left turn signal lamp to the converter. Make sure this connection is not loose or broken where it ties into the taillight, usually right behind the taillight plug.
These things are a big pain and no fun to change in -20.
That is what happened to mine.
On my trailer everything worked except the turn signal.
Traced wires, checked & rechecked grounds.
I pulled the rear light housing out of the trailer, put the blinker on, put a test light on the hot side of the light plug & it blinked.
The aftermarket converter box tucked in behind the tail light was shot. It "looked" fine but no way to test it. I just replaced it for $48 & it was good to go.
yes it would be a pain in cold weather unless you had a heated garage.