Headlights Quit!!

[gvt]

My headlights quit working, but all of the other lights still work. I do have the headlight booster wiring installed and I've checked the connections and the grounds. I'm suspicious of the switch. Does anyone have any suggestions? Is there a way to test the switch? Thanks.

[diesel65]

If you have the booster harness then first unplug the old light harness from the booster and reconnect the bulb to the old harness and see if the bulb works now, If it does then the problem is in the booster harness, if not, then the headlight switch might be bad.
Did you check that you have power to the booster relay?
If you have a 12v test light pull out the dash and back probe the switch, the red wire is pwr feed to the switch and the yellow wire is the feed to the dimmer switch.
There is a lighting fuse in the engine bay fuse box...50 Amp, but if your park lights are working, then this fuse should be good.

[Dvldog 8793]

Howdy
Did you check to see if the booster kit relays were getting 12VDC at the switch terminal and at the supply terminal? Can you hear the relays engaging? The best way I can think of to cheack the headlight switch is to take it out and OHM all the positions to see if they work. I think thoses switches were a real problem for GM as they ran full light current through them.( I think???) If the relays are good and NOT engageing then I think you have a switch problem or the headlight fuse.
L8r
Conley

[gvt]

Thanks for the replies, I really do appreciate it! Everything checked out OK, including the switch. I realized that I had not checked the high-beams, so I flipped 'em on and all four came on like they should. I went back to low-beam and they worked too. Now I'm really confused! But, all is well, I have turned them on/off and cycled the high/low beam a bunch of times and everything seems fine. Maybe the high/low switch is getting bad? Thanks again!

[markrinker]

Howdy neighbor! (Elk River to Maple Grove, MN is like 15 miles, for the rest of you guys out there...)

By chance, is your truck equipped with a plow? If so, you might have a problem with the relays that control the plow lights.

[fastcat800]

I have installed a relay to get all four headlights to work at the same time on high beam. This weekend I had the high beams on longer than anytimne since installing the relay. It was late at night out in the boonies in northern Minnesota. The highs were on continous for 15-20 minutes and the head lights went out. I instinctively hit the low beams and they came back on. Hit the highs again and no lights. Put it back on low and tried the highs again in about 5 minutes and they all worked again. I figure the relay can't handle the power required to run all 4 headlights for continous duty. It seems only good for a 10-15 minute duty cycle.

[gvt]

Mark - No plow here!

In my case it just took a flip of the high beams to get things working again. It hasn't been a problem since. I have run the high beams for extended periods without any problems. I think my blinker/high beam/cruise switch may be going bad, the blinkers have been acting up a little lately. Thanks again!