After Installing New Breakaway Kit on Trailer the Brakes Lock Up when Connected to Different Truck

Question:

I have a dual axel big Tex trailer 12 foot like an idiot I forgot to plug the molded wiring harness in and drug I it about 30 miles needles to say the plug was ruined. I bought a new molded harness and while rewiring noticed the original break kit had water and a corroded battery. So I bought a new kit one that shows full charge half charge dead has 3 lights in it green yellow red which I assume is used for travel trailers with a battery source any way I rewired wire for cut one put the new one on cut another and so on pulled the trailer with my Chevy pulled fine all wheels turned a friend hooked his Tacoma up plugged it in rear axel was dragging wheels locked up. I hooked my Chevy back up to it pulled trailer approx 100 miles got home unhooked it all was fine, next day came out both rear tires were ate up wore down and had to flats. Could the brakes be stuck because of the kit noticed no hard pulling trailer felt like it was pulling normal thanks for any help. About to go jack the axel up plug it in and see if there is any drag to the wheels ps front axel tires are fine

asked by: Ronald F

Expert Reply:

It sound like you are describing the Engager breakaway system, # 20099, or something similar. The lights indicate the charge level of the breakaway battery. The issue when you plugged in the trailer to the friend's truck could mean that the connector on his truck is not wired the same as it is on your truck and trailer.

I imagine that if the brakes were locked up when the trailer was connected to your truck you would have heard the tires scraping the ground or someone would have flagged you down, especially after a 100 mile trip. I believe that the flats were caused by the previous time the tires were dragged.

To make sure everything is wired up correctly take a look at the installation details I have linked. I have also included a link to our wiring help article that shows how different vehicle and trailer side connectors are wired. And I have linked a help article on testing breakaway systems for you.

expert reply by: Michael H