96 Blazer Headlight Cycling

[CEO Wrench]

My daughter's 96 Blazer headlights cycle off, on, and between high and low beams intermittently, with the switch in the "on" position. It has the daytime running lights, but not the auto on/off.
I've checked the forum but haven't found anything on this. Anyone know something about this?
Thanks

[rlith]

Originally Posted by CEO Wrench

My daughter's 96 Blazer headlights cycle off, on, and between high and low beams intermittently, with the switch in the "on" position. It has the daytime running lights, but not the auto on/off.
I've checked the forum but haven't found anything on this. Anyone know something about this?
Thanks

If you have the DRL's the sensor is on the top of the dash I believe. Are you looking to disable them? Not sure I understand the question.

[CEO Wrench]

Originally Posted by rlith

If you have the DRL's the sensor is on the top of the dash I believe. Are you looking to disable them? Not sure I understand the question.

rlith:
She's not trying to disable the DRLs; just eliminate the cycling off/on/hi beam/low beam. I would guess there's an electrical short somewhere that causes the breaker to cut out intermittently, but I'm puzzled why it also cycles between high and low. She's in CA and I'm in Michigan so I can't look at it myself and try to replicate the problem, unfortunately. I'm familiar with the dash switch and the high/low switch on the column, but I was wondering if the 96s ran any of the circuitry through the EBC and that could be the cause, or if there are relays controlling the high/low or off/on.
I have a 98 Jimmy and I know the circuitry's somewhat different that her 96 Blazer.
Thanks for any help you can give. In reading your other responses, I can tell you're a real pro and give excellent advice!

[wolfox]

Headlight switch may need to be replaced. Before that though, I would backprobe the headlamp bulb sockets to make sure that there are no shorts first. There is a thermal breaker in the headlamp switch that when it senses an overload, will cycle on and off. If you have DRLs, it will look like the truck is switching from high/low beams by itself when the headlights are turned on. If you have eliminated the possibility of short circuits, then I would blame the switch - they sometimes fail oddly as you describe when they age. $20 and half an hour of your time is all that is needed to replace it if your mechanically savvy. If not, buy the part and drop the works off at your local, trusted mechanic's shop. He/She can take care of it for you really fast and easily.