Trailer Lights Stay on Once Vehicle Ignition is Shut Off

Question:

Have a problem with my trailer lights staying on very dimly after everything in truck is turned off. Have to disconnect the 7-pin connector to get the trailer lights to go off. Problem is not there if I just hook up the trailer before doing anything with the truck. Its not the delay in the truck lights after you turn off. The trailer lights will stay on for a LONG time if not disconnected.

asked by: Zzmike

Expert Reply:

I suspect your problem is caused by a damaged or corroded trailer connector.

Take a look at your trailer connectors, both the socket on your truck as well as the plug on the trailer. Look for green or white corrosion on the pins or sockets of the connectors. If corrosion is visible, there is a strong possibility that the corrosion has spread to the interior of the connector. The terminals that each individual circuit connects to are very close together, if corrosion builds up on the terminals, the 12-volt accessory circuit can actually bleed over to the other circuits and apply power to them.

Clean or replace the trailer connectors as needed, which should solve your problem.

expert reply by: Mike L

Scotty

3/7/2013

I have exact same problem with 100 new equipment that I purchased from eTrailer. So though the theory of cross connection e.g. frayed wire, is still valid, I have verified that all my connections are tight. Any other ideas for why a very dim light exists as explained previously?Thank you.

Patrick B.

6/20/2013

Corrosion in the connectors, 7-way on vehicle or trailer, is the most likely culprit. If all of those parts are new and properly installed, we have seen this happen with LED trailer lights. There may be a small amount of power on the taillight circuit, not enough to light the vehicle or trailer incandescent bulbs, but maybe enough for an LED. You can take a circuit tester and probe the wires of the light that is dimly lit to find which circuit the current is on, and more closely examine that circuit. It could be a relay, somewhere on the fuse blocks, is going out.