Wiring Solutions for a 1968 Chevy Truck

Question:

someone has already hooked up a 4 flat trailer connector at one time which no longer works iam trying to install a new 4 flat brn,grn,yel,wht. but the old one is red,blu,wht,yel. and the stock wiring is not the same colors as wiring diagram in trucks servive manual so i need to know which colors to splice into.

asked by: David F

Expert Reply:

Since the wiring you have is not the traditional wiring colors for a 4-way, and the colors do not match what is in the service manual for you vehicle your best bet for wiring up the new 4-way would be to use a circuit tester # PTW2993 and wire by function. Check out the FAQ article I attached on trailer wiring for you to check out.

The easiest way to wire by function would be to test each of the wires you found on your 1968 Chevy Truck for voltage when the different tail light functions are being used. For example, with the key on turn the left blinker on and then test the different wires for intermittent voltage. The wire that has intermittent voltage will be the left blinker circuit for your new 4-way and should be run to the yellow wire. Repeat this process for the remaining circuits.

expert reply by: Jameson C