Troubleshooting Trailer Reverse Lock Out Solenoid that Doesn't Work

Published 01/28/2015

Question:

Hi- purchased T4748800, brake solenoid with reverse lock out and having issues with the reverse. I am getting power and hear it click, how do you test it further? Cab it clog up some how?

asked by: Rick A

Expert Reply:

If the solenoid is getting a full 12 volts and is grounding properly it should be shutting all the way. Since you said it is clicking that makes it sound like it's getting power. You could try improving the ground circuit but most likely that's not it.

Is it possible the brakes are also activating while moving forward and the solenoid isn't at fault?

Typically if a reverse lockout solenoid is getting power and grounding properly and it still isn't working it needs to be replaced. If the solenoid is brand new it could be faulty. Since it has to be taken off anyway you could try removing the brake line from the output side of the solenoid, putting your vehicle in reverse and have a friend watch to see if fluid get pumped out of the solenoid when you attempt to back the trailer up.

expert reply by: Jameson C