Dodge Repair Questions? Ask a Mechanic for Answers ASAP
First thing to check is grounds to the taillights. Try connecting a jumper wire from a good ground to the black ground wire at the left taillight. See if this fixes the problem. If it does, permanently connect new ground wire. Let me know what it does.
Ill check schematics and get back to you in a bit.
If grounds are okay, check any trailer wiring to make sure none of it is shorted. If all looks good there then your problem will be in the combination flasher, located under drivers side of the dash.
Thanks for the update, please let me know what you find after you've had a chance to check it out.