I drive a 1996 Chevrolet Cavalier Z22. When I turn on the headlights the "ext lamp" fuse blows and my dash board, break and signal lights go out. But when the headlights are off and I hit the breaks the tail lights turn on and the signals will still work. I have replaced all of the bulbs that are effected and the problem still exists. If someone could provide some additional information it would be greatly appreciated.

 

Well, there's definitely some kind of short circuit between the headlight control (the left arm on the column) and the wiring that goes to the headlights... could be the switch itself, hard to say without replacing it to see.

Have you done any modifications to the wiring to the headlights? HID's or other conversions? Car ever been in an accident? Maybe a wire is pinched somewhere along the line.

If you have a multimeter, I would test all the external lights checking for ground faults... disconnect the battery, then put a new fuse in the EXT LAMP spot. Then turn on the headlights switch (but of course, the lights won't come on as the battery is disconnected! so therefore the fuse shouldn't blow). Then start checking all the lights for continuity on BOTH terminals to ground. When you find one, that's where the short likely is. It's going to take a lot of hunting, unfortunately... unless you can find a spot on the wiring harness that is obviously damaged.