Troubleshooting Humming Brakes and Malfunctioning Trailer Lamps on 2005 Corsair 5th Wheel

Question:

I have a 2005 Silverado hooked up to a 2005 Corsair 5th wheel trailer. Ive never had a problem with the trailer lights in 8 years, however, last year we were not able to use our trailer for a year due to a health problem. While not using our trailer, I swapped out the 5 clearance lights at the rear of the trailer with LED lights, when I turned on the truck light switch all the lights worked fine. However, when I stepped on the brake pedal, I heard a buzzing sound possibly coming from the trailer brakes. Also the left rear brake light did not come on and the right brake light only came on faintly. The signal lights worked fine. When I turned on the 4 way flashers, it was a similar problem with some of the clearance lights flashing faintly and the left brake light did not come on. I thought my switching to the LED lights may have caused this problem, however, there are only 2 black wires coming out of the trailer to the clearance lights which I assume are wired in series so I dont think that is the problem - any ideas what may be causing this??? Thanks.

asked by: Don O

Expert Reply:

It is normal to hear some humming from the brake magnets when the brakes are applied, but if they are worn, the humming might be louder. You'll want to examine your magnets by pulling the drums and checking the magnet wear surfaces. If the surfaces are worn away to the point where the copper windings are showing through, then the magnets should be replaced.

As far as the brake light signal bleeding into the clearance light situation you described, you're describing a ground problem. Trailer lights would ground in one of two ways, either by a separate ground wire that needs to be connected directly to the trailer frame, or by its mounting stud being in direct contact with the trailer frame. If this ground connection isn't made to the trailer frame, it would explain the problem you are having. Check the ground connections on the lamps you recently replaced, making sure the ground wire is securely attached to clean metal on the trailer frame. If the lamps don't have a separate ground wire, you'll need to run a jumper wire from the mounting stud to the trailer frame, which will complete the ground circuit.

expert reply by: Mike L