2002 DHS Hi Beams work during daylight hours, NOT at night.

In daylight whether twilight sensor on or off hi beams work using both flash and full on. Cover twilight sensor (daylight test suggested by experienced auto-electric technician) and hi beams still work fine. Night comes and hi beams will not flash or go full on--that is, low beams go out and it gets really dark; kinda scary when driving. Doesn't make sense to me... auto-electrical tech suggested replacing light control module. That also doesn't compute for me.

Suggestions and/or solutions greatly appreciated.

It turns out this is more than a weird headlight problem. It is some kind of weird electrical problem.

When high beams go away so too do the following functions: the fuel door will not open, the trunk will not unlock (button or fob) and although the doors will lock from the key-fob the horn does not honk to notify of locking. I have checked these on several occasions and they always stop working when the hi-beams stop working.

None of these mal-functioning items are show stoppers by any means: I can live without hi-beams just fine, I can open the trunk with the key and then the fuel door without problem, and... really... do I care that the horn doesn't honk when the doors lock? Not really.

That said, the whole set of (related?) problems bug me and I would like to solve them.

I have looked for electrical diagrams showing how the fuel door, horn and trunk are related... if they are, and found nothing. Theone thing common to the problems is heat. I live in the Southern Utah desert are where high-90s to tripple digits are daily occurances in the summer. So, for example, if I take 2 mile run to the store and hi-beams work when I leave, they will, typically, not work when I get to the store. My assumption is the heating of electrical system coupled with the ambient heat cause the problems. And, yes, the same problems crop-up during cooler weather too... but not as frequently because it takes longer drives for them to appear.

The system fuses have been checked and are O.K. and the relays have been tested and found O.K. By the way if I swap relays about, the problems still occur. I am at a loss and will gladly test any theories offered and report back. Thanks

 

I'm inclined to go with your tech friend. It sounds like the sensor is confused.

I don't know if there is an Oldsmobile out there with the same twilight system or not. If there were, I'd recommend you get the Olds parts. In the old days, Oldsmobile parts were less expensive by half or more.

I was looking around to see if someone else was having the same prob I am. My high beams don't flash to pass and the low-beam bulbs have no power when I switch to high beams. Makes me think the dimmer went bad, but I really don't want to start pulling the wiring at the column apart to replace the switch (located on the left side of the column under the dash). Every time I do that to a car, I manage to discombobulate something else.

Good luck with finding a solution,
Wendy