Troubleshooting a Trailer with No Tail Light Or Blinker Functions

Question:

Hi, I have a 1977 concord camper trailer, the side markers, electric brake, lights work but no tail,brake or turn signal either side, help please, this is my hunting camp and time is of essence.

asked by: Alex S

Expert Reply:

The best way to track down wiring issues is to get a hold of a circuit tester like a Circuit Tester Kit # PTW2993 and test the circuits to track down the problem. The first thing you will want to test is the 7-way from your vehicle for voltage on each of the circuits when the correct trailer light function is being applied. This will tell you whether or not the problem is in the trailer or in your tow vehicle. Check out the picture I attached to see how a 7-way should be wired.

If your 7-way has voltage in all of the right places, then it is time to connect your wiring from your trailer to your vehicle and then begin testing the taillight wiring of your trailer looking for corrosion and exposed wiring. Most likely it is a ground issue that is causing the problems you are having.

If the 7-way does not have voltage on the right circuits then you will need to first check the back of the connector that is on your vehicle for any loose wiring or corrosion and then trace the wiring back. You will want to trace the wiring back checking for voltage frequently looking for voltage to rule out where the bad wiring is.

I attached a couple helpful links for you to check out also.

expert reply by: Jameson C