Thread: Electrical problems?

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I got a problem I think with my wiring? I have a 70 chevelle and the wireing is not the best from the previous owner but anyways the dimmer switch on the floor was bad (had to hold it down for the brights to work) so I replaced it. Well one day driving home from the bar I hit the brights and all the electrical went out? I had no power anywhere? I unpluged it and still nothing? The next day my dad and I were playing around with it and figured out that if the lights were turned off it would start? Maybe I am thinking to hard. But if you turn on the lights or even hit the breaks the car dies, I dont understand why it is doing this after all this time? Anyone have an idea? I am open to all suggestions! Thanks, Brian

Might better start by getting a copy of the wiring diagram for that car. Headlights and brake lights are unswitched,and so should be live with the key off. If hitting the brakes shuts off the car, then you either have a short between the brake light switch and the taillights or when they pull power,it takes away from ignition,which would indicate power supply problems,even something as simple as a bad ground cable can ruin your whole day. Start by checking all connections,and make sure its charging,and when it is it's making it back to the battery. Hope this helps you, Hank

You have a poor connection somewhere. When the lights try to come on, the draw is too much for it, every thing goes out. Check the battery cables, especially the one on the starter solenoid. take them apart, clean everything up, and it should work. Check the cable ends, too, sometimes they are internally flawed. You can solder them, but probably better to get a new one. Those repair ends that clamp on to the cable are famous for glitches like yours.

Also double check your grounds starting from the battery working your way to the body grounds. When grounding is not present, the electrical supply will "look" for a path and does not have a way to flow. As soon as something interupts what little current that is using feedback from lack of ground, it robs what little amperage being used to operate that system and falls below what is required to run it. It seems too coincidental that the majority of the system started showing these signs of no power all of a sudden. After you check every possible ground solution and it still has fits, then it's time to do good old detective work.

Hey, great tips guys, thanks! I will see what I find!!
Brian

I was driving a relative's 39 Ford one nite and everything was going great until I stopped for gas. Car restarted but not the lights. Had to use a flashlight to drive about 5 miles until a guy in a PU saw my problem and got in front of me to help get me home. (Country roads can really be pitch black when you got no lights) Turned out to be a bad ground on the floor dimmer. Not having the right part, I circumvented the problem by wiring in a toggle until I could get the correct parts.

It really is the little things that will drive you nuts.