Troubleshooting Wiring on 2006 Toyota Sienna Lights Work on Cargo Trailer Not on Tent Trailer

Question:

i have 2006 toyota sienna with brake control and tent trailer. i use wiring module to connect to tent trailer has trailer brakes with 7 pin connector. the trailer side signal lights braks and hazerd lights are most of time is not working when i tow with 2006 sienna and tent trailer. some times works. always brakes, signal lights are working when i use my friend 2019 pathfinder or 2015 toyota tandra to tow the tent trailer. i hock up other cargo trailer with trailer brakes then cargo trailer lights are all works with 06 sienna. only does not work with sienna and tent trailer. i changed trailer light bulbs. i repaced to new wiring module for sienna. checked all wires and connectors for car side and trailer side and all good. when lights are not working the signal light power has right at module but it does not have power right after module. so found no power to trailer side after module. i check conduction of grand wire and car side and connect good. now i do not know why its not working. please give me some advise.

asked by: Tak

Helpful Expert Reply:

Based on the information you have provided, the best advice I can give is to move your ground wire to a more suitable location. Make sure it has a good, clean connection when you do.

Often times with strange situations like what you have described it, is the ground wire causing the issue. Since the electrical load of the cargo trailer would likely not be as much as the tent trailer, a weak ground connection would potentially explain why the lights are working with the cargo trailer and not the other.

I have attached a helpful article on troubleshooting common wiring issues for your reference.

expert reply by: Robin H