Electrical Problem

[ratzlaff]

My headlights are intermittently turning off.

When I turn on my AC or rear defrost my front headlights turn off.

So that makes me think battery/alternator. The first time I checked the voltage it was 14.5V with the engine running. I checked it when the lights were acting weird it; it was down to 13.8V. Is that too low?

But none of my other lights act the same way. My backing up lights do not flicker at all or turn signals.

The main thing that I think is odd about this is the brights. Usually I have 3 modes for headlights. Normal headlights on, brights on, or both normal and brights on. When my lights are off I cannot turn on my brights, but I can turn both of them on. So that makes it sound like a short. It doesn't make sense if I am low on power that I can turn both my lights on, but not either or.

What are you opinions on the matter? Suggestions? I will be taking it in to get the battery/alternator checked at Autozone tomorrow.

Thanks!

[Tech II]

13.8 volts is not low......

Your battery puts out 12.6, to charge it the alternator has to put out a voltage higher than 12.6.....as a vehicle warms up and it's rpms drop, alternator output will drop also.....but should be at least 13.0 volts at idle, with no load....if it has a load, it will be less at idle, but if you rev the engine higher, the output should increase....

"Usually I have 3 modes for headlights. Normal headlights on, brights on, or both normal and brights on. When my lights are off I cannot turn on my brights, but I can turn both of them on"

Could you clarify that?

[ratzlaff]

Yeah, sorry.

I guess not all cars do this.

I have my normal driving headlights. I have my brights. So I can drive with my normal headlights on, my brights on or both my normal and brights on (so like a super bright mode).

So when my headlights are out I cannot turn on my normal headlights or my brights by themselves. But I can turn on both at the same time (super bright mode).

I just got back from autozone. The battery/alternator check out. So I guess its a wiring problem. Bad grounding or a short. Any ideas on where I should check?

Thanks.

[ratzlaff]

I spent a while looking into this again. I am pretty sure it has to do just with my AC unit. No other systems seem to affect the headlights. I sometimes hear a clicking after/while I am messing with settings on the AC unit. It sounds like a relay is turning on and off?

Anyway, I think I came up with a viable workaround. I have the automatic lights in my car. So when the sensor senses low light the headlights turn on. So I messed with the manual headlight switch (which I have never touched since I bought the car) it seems like that can turn on the headlights regardless even if they are "off" (When I say "off" I mean they are supposed to be on, but they are off).

What are your thoughts on the matter?

Hope I was clear...I have trouble explaining myself sometimes.

[panzer dragoon]

(front) Headlights all the way off? -Or do they just dim? With this condition.