My batteries getting drained with my lights on. The truck has a GM internally regulated alternator. However, the power to the headlight switch is run direct off the hot side of the solenoid, then runs power to the ignition. There is also the wire to the batt post on the alternator then the wire going from the batt post into the plug and the other wire runs out of the plug to the ignition. How is this circuit working? As I see it my lights are pulling direct off the battery. Should my lights be tied into the wire coming out of the alternator? PLEASE HELP!

 

The usual wiring gets the power from the starter relay (battery post stud) runs through a fusible link to the H/switch & fuse box.

Don't fret about it ... Franklin will be by here soon with a schematic.

 

Thanks Mil1ion. I could really use a drawing of some sort. This is no where near stock wiring and I've shaken my head a number of times already at the hack wiring job on this truck. There are some things that I can't figure out how it should run though. The gut before me made things work but not right. Look forward to that schematic.

 

Do mean the battery goes dead even though the truck is running?

This is ok. The factory runs the headlights from the same place, only with a fusible link like Dennis said. The headlight switch has a built-in circuit breaker for the headlights.

There should be a wire going from the output of the alt to the battery post of the starter solenoid(the same place as the headlight wire is hooked). This is what charges the battery and should be about 10guage wire[/quote]

The plug has two small wires. One is the voltage monitor for the internal regulator, and is tied to the output wire of the alt. That's what this wire is.

This other wire in the plug is the signal from the ignition switch to put the alternator "online". If the alt is "online" all the time, it will run the battery down. Also this wire should have a "alt" idiot light installed in series. This is necessary if this wire is tied to the same wire that feeds the coil. Otherwise voltage will feedback from the alt and the truck will not turn off. The "alt" light is also a nice feature to tell you if it quits working or the fan belt breaks. Go to the parts store and get a panel light with a plastic socket and two wires. Hook one wire of the light to the wire that goes to the alt plug, and hook the other wire of the light to the ignition switch.

The headlights wired directly to the battery is correct. And the alternator is also hooked directly to the battery, so they are one and the same. The heart of the whole system is that one large connection post on the starter relay that has the big cable that goes to the battery. The battery, alternator, and the whole truck's electrical system is fed from there.

Don't let me miss-lead you though on the correct way to hook the headlight switch up. The headlight switch has many circuits in it. The headlight circuit is fed directly from the battery, but there are seperate circuits in the headlight switch that are fed from fused circuits. The running lights are fed from the fuse box, as are the dash lights fed from another seperate fuse.

 

Franklin2,
Man thanks for all that info. The truck is fine when it sits. The problem is at night when I'm driving with lights on. The next morning the batt is dead. It sounds as though things are hooked up correct. I will need to put in afusible link and an alt light. Eventually I will get a new kit from painless because as the truck sits there is no fuse block of any kind. I'll check everything tonight with your info. Thanks again.

 

You might want to get a cheap voltmeter, and check the battery voltage with the truck off.

Then check it again with the truck running.

The running voltage should be higher, and this tells you it's charging. You might want to monitor the voltage also with the lights on(and the truck still running). With the lights on the voltage may drop a little bit, but it should still be higher than the reading with the truck off. Worst case with the lights on, the voltage reading will be the same as with the truck off. If the voltage reading with the lights on is lower than the reading with the truck off, then you have problems.