Battery Drain
Thread Starter
Racer
Joined: Jan 2008
Posts: 299
Likes: 4
From: Surprise AZ
Battery Drain
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? 
Racer
Joined: Jan 2014
Posts: 287
Likes: 8
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?..
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Intermediate
Joined: Sep 2014
Posts: 45
Likes: 9
From: Queensland
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.
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.
Team Owner
Joined: Mar 2000
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From: Down in Bulldog country
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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.