joescvette

1978 has a battery drain on the courtesy fuse line. Pull the fuse o reading, replace fuse, I get 12.9 reading, on the neg cable side. everything off. I took off the neg. cable and put a multimeter dc volts between. Is something wrong?

Giant_Robot

Explaining your problem in English might help.

joescvette

In the fuse box the interior light fuse, has a drain. Take fuse out no drain. Replace fuse I get a 12.9 reading on my multimeter.

Giant_Robot

Is the door open, or are you in the car with the door closed at this point?

door open = interior lights on.

joescvette

Door open interior lights off. Everything is off.

Giant_Robot

If your courtesy timer delay is anything like mine was.. it will be hot to the touch. Its located under the dash in the middle, might want to touch that.. then remove it, and splice your lines together to get the lights to turn off, just there will be no delay. possible the drain is there?..

Giant_Robot

if the door is open you are opening a circuit to turn on the lights.. close the door. You cant really test a drain with the door open. Do your interior lights even work?

joescvette

When I replace the fuse everything works normal. The timer works fine. Everything in the car works. My charger keeps charging with fuse in. With fuse out it doesn't.

Spoticus

My 78 had a current drain on the courtesy fuse line as well.
Main culprit was the security relay for the original security system (170mAmp). The relay is located down near the shifter in the centre console. Do you hear a relay click in that location when you plug the courtesy fuse back in?
I just unplugged the relay and left it there as I have a after market security system installed.
Other drains on that circuit were the after market security system (20mAmp) and CD Radio memory (1mAmp).
If the doors are open and all the interior courtesy lights are on the current drain was around 2 Amps.

joescvette

The org. security system works. Could that still be the problem?

69L46

I would suggest locating a wiring schematic for your car and seeing what else might be involved. Using a non-contact voltage tester might make it a bit easier to isolate at what point the current stops flowing if you try to remove components.

joescvette

Thanks I will try every ones suggestions.