With some vehicles, there is a multi-wire connector at the rear, take the connector loose and all the rear lites are disconnected.
Also take the connector loose at the headlite switch. Usually the headlite switch has two sections, one is a circuit breaker only for the headlites, gets voltage from a fusible link. The other section is a fused circuit, usually for the tail an dash lites.
You can use a testlite, find a wire at switch connector that is hot all the time, doesn't matter which hot. Use the testlite between the terminal for the hot wire and terminal for the brown wire, hopefully, there is only one brown, that should be for the tail lamps. If the lites at the rear are disconnected, the testlite should not come on. If it comes on, and stays on, the circuit is going to ground somewhere ground. Rather than hunt a short on a long circuit, I just splice in a new wire front to back. I clip the old wire at the headlite connector and the rear connector, leave a long enough pigtail to splice the new wire. Just for testing, I let the new wire lay on the ground, twist the connections together at both ends, turn on the headlite switch, see if everything works ok? If everything is ok, properly route the new wire, make the connections permanent.
You need to be sure you find the correct circuit that has the short, hopefully there are no unknown branches off that circuit. Took me longer to write this than it does to do the work, or seems like it.
Friday, August 7th, 2009 AT 9:03 AM