78 Electrical Problems
Thread Starter
Racer
Joined: Jul 1999
Posts: 490
Likes: 7
From: Cincinnati OH
78 Electrical Problems
I'm having a difficult time locating the source of a 145-150 milliamp continuous drain on the battery of my '78. I've narrowed it down to accessories fused at the CLK LTR ANT FUSE. Here are the symptoms:
1. Clock stopped working completely.
2. Radio loses time and presets right after turning the car off.
3. Power antenna works fine. Problems started occurring after the motor replaced though. However, the motor does not run when the car is off, and the drain still exists if I disconnect the wire harness.
4. Drain continues if I disconnect the cigar lighter.
Any suggestions or recommendations (before I go tearing out the center instrument panel) would be appreciated.
Thanks,
Eric
[Modified by Ominous C5, 9:02 PM 8/6/2001]
1. Clock stopped working completely.
2. Radio loses time and presets right after turning the car off.
3. Power antenna works fine. Problems started occurring after the motor replaced though. However, the motor does not run when the car is off, and the drain still exists if I disconnect the wire harness.
4. Drain continues if I disconnect the cigar lighter.
Any suggestions or recommendations (before I go tearing out the center instrument panel) would be appreciated.
Thanks,
Eric
[Modified by Ominous C5, 9:02 PM 8/6/2001]
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Re: 78 Electrical Problems (Ominous C5)
Since the "Problems started occurring after the motor replaced" is it possible that you pinched a wire someplace. Sure sounds like 12v is shorting to ground in that circuit, but not a good contact to gound, maybe still some insulation left between the wire and whatever is pinching it.
Drifting
Joined: Feb 2000
Posts: 1,607
Likes: 0
From: Clarksville,Tn,USA TN
Re: 78 Electrical Problems (wombvette)
Eric,
also drawing power from from that circuit is the anti theft Circuit and the Power door locks which are hot all the time.
The anti theft has 6 switches-L/H and R/H courtesy light switches, the hood switch, the anti theft warning switch which is activated by removing the control switch and the 2 roof panel switches if yours have them. If one of these switches close and the relay energizes it could draw current to the alarm horn if it works until the battery drains. Do you have an 78 electrical troubleshooting manual?
One of your door lock switches could be bad allowing current to flow.
also drawing power from from that circuit is the anti theft Circuit and the Power door locks which are hot all the time.
The anti theft has 6 switches-L/H and R/H courtesy light switches, the hood switch, the anti theft warning switch which is activated by removing the control switch and the 2 roof panel switches if yours have them. If one of these switches close and the relay energizes it could draw current to the alarm horn if it works until the battery drains. Do you have an 78 electrical troubleshooting manual?
One of your door lock switches could be bad allowing current to flow.
Advanced
Joined: Jun 2001
Posts: 68
Likes: 0
Re: 78 Electrical Problems (Ominous C5)
Eric,
Take a careful look around the dash to make sure nothing is shorting out somewhere along the line.
Try to trouble shoot the problem by disconnectiong random dash elements to make sure they are not causing the drain.
-Tom
Take a careful look around the dash to make sure nothing is shorting out somewhere along the line.
Try to trouble shoot the problem by disconnectiong random dash elements to make sure they are not causing the drain.
-Tom
