There's an auto-resetting circuit breaker built into the headlamp switch. The circuit is very simple and straight forward, not like on the newer complicated vehicles.
Start by unplugging one headlamp bulb. If the other one stays on, suspect too much current due to having the wrong bulbs installed. They should be 9004s. If the bulbs are correct, the next likely suspect would be a corroded splice or the wiring connector on one of the switches or where the wire goes through the firewall connector. Unplugging one bulb will cut the current flow in half which could also affect a bad connection or splice. The reduced current will cause less heat buildup at the bad connection. The easiest way to troubleshoot this is to connect a test light in various places in the circuit to see how far the voltage is getting and where it is lost.
caradiodoc
Sep 23, 2009 at 11:11 AM
