headlight problem - car is evil

[cozykat]

Originally Posted by kwren

And of course, if the headlight relays are "after" the fuses, and they are, relay points stuck would be a mute point when the fuses are removed... the lights stay on. The voltage that keeps the lights on even with the headlight fuses removed has to be coming from the security system.

Opps! Apparently the logical part of my brain experienced a malfunction.

Originally Posted by kwren

There are more than one for headlights. I have two different diagrams but there may be several. One wiring diagram with security system and one wiring diagram without the security system. Naturally, both are fused to eliminate the power supply to the headlights when the headlight fuses are removed.

With the security system in the equation the power to cause the lights to be on with the headlight fuses removed "comes in the back door", but it has to revert back to the security system.

Of course there are additional relays involved in that part of the equation as well.

Keith

I understand what you are saying and it makes sense. Tania sent me some diagrams with the security system.. I will try to look that over as well - after all it might one day help me identify the short that the aftermarket alarm causes in my car.

[cozykat]

Originally Posted by svxistentialist

Wannarace, have you asked Jason about this? Is he clued up on the electrics?

It occurs to me there could be one simple solution. I think you mentioned you have the wiring diagram? Well, my understanding of these diagrams falls well short of engineer level. However I noticed a couple of diodes in the circuitry. Diodes are electronic one way valves put there to ensure the current only goes where you want it to go. If one of your diodes was shot, it could be allowing current to leak back to your headlamps. Diodes are cheap. It might be cost effective to just replace the ones in the diagram and see if your problem goes away.

Joe

There are 2 sides to a diode; the anode (the positive side) and the cathode (the negative side). To turn on a diode (forward bias), the anode must be more positive than the cathode. When its on, the diode simply acts like a wire. To turn off a diode (reverse bias), the anode must be less positive than the cathode. When off, the diode should act like a cut in the wire.
Diodes aid in preventing feedback on a line but over time they can break down and in your case allow a small amount of current flow into one of the security relays. I don't recall if diodes slowly break down or plain fail but as Joe mentioned they are pretty cheap (like $1 cheap), you just need to see where and the kind of diode that is installed. Then hit up a local Radioshack or some place similar for a replacement.

some cute diodes: