When I back up my trailer the brakes lock up?

sounds like your electric trailer brakes are being activated when you put your vehicle in reverse.most likely caused by back-up lights wired into your vehicle connector where the brake activator should be.

jeff
March 2008

If the trailer is relatively old it may well have a loccking bar on the side of the drawbar which needs to be manually engaged prior to reversing, i used to have a trailer like this and it a complete pain in the ass

chris
January 2008

most heavy duty trailers have a pin in the bar which connects them. when pressure from the trailer pushes this it applies the brakes. sounds like the trailer you have is sensitive to this so when you try to reverse its putting the brakes on, but when you remove the power its fine. maybe a service would sort that out. Hope it helps.

T Watson
December 2007