Severe Battery Drain

[Michael M.]

The battery in my '68 suddenly died after sitting for a few days. I recharged the battery, but then the next day, same thing. I have a key off 4 amp battery drain (pretty significant). I've gone through the procedure of pulling the fuses one by one with no luck, the reading doesn't fluctuate one iota. Out of exasperation, I pulled all the fuses at the same time, and still reading a 4 amp draw.

It seems I have an unfused circuit somewhere pulling 4 amps. Can anyone assist me in where to start looking and what to do. So if it's the alternator pulling the draw, I should disconnect the alternator and see if that reduces or eliminates the draw. Correct? Same with the starter? And horn relay?

Anything else I should be looking at? Thanks for any replies.

[Erv M.]

Re: Severe Battery Drain

The answer is YES. Disconnect one at a time and check the results. My guess will be the alternator.

[Edward B.]

Re: Severe Battery Drain

4 amps is quite significant - the alternator is the most likely culprit.

[Jim T.]

Re: Severe Battery Drain

Michael I have a 1968 and have experienced battery drain. When the car was not being used I was cleaning the dash and the wiper switch was moved from off to on.
Returned the wiper switch to the off position.
Battery was dead the next time I tried to start my 68.
What has to be done if the wiper switch is moved to on, start the car, turn on the wipers and let the wiper door come up and the wipers make their movement across the windshield, then turn them off. This will stop the drain on the battery and all is well, turn off the engine.

[Terry B.]

Re: Severe Battery Drain

Michael I have a 1968 and have experienced battery drain. When the car was not being used I was cleaning the dash and the wiper switch was moved from off to on.
Returned the wiper switch to the off position.
Battery was dead the next time I tried to start my 68.
What has to be done if the wiper switch is moved to on, start the car, turn on the wipers and let the wiper door come up and the wipers make their movement across the windshield, then turn them off. This will stop the drain on the battery and all is well, turn off the engine.

Jim,

Wouldn't having a battery disconnect prevent the drain on the batttery? A 4 amp drain sounds like a disaster waiting to happen if there is some type of other malfunction or short.

I have heard of a wiring problem involving '68's and the wiper motor that was corrected later in production. I'm not sure if that is correct however. Searching the archives might shed some light.

Terry

[Jim T.]

Re: Severe Battery Drain

Jim,

Wouldn't having a battery disconnect prevent the drain on the batttery? A 4 amp drain sounds like a disaster waiting to happen if there is some type of other malfunction or short.

I have heard of a wiring problem involving '68's and the wiper motor that was corrected later in production. I'm not sure if that is correct however. Searching the archives might shed some light.

Terry

Terry my one and only incident of the wiper switch happened about 30 years ago. When my 68 is parked in the garage the negative battery is disconnected from the frame.

[Mark F.]

Re: Severe Battery Drain

Michael
I had a battery drain on my 68 for years so I went to the battery cut off switch. I finally figured out my problem. When I was turning off the ignition I was actually stopping at the accessory spot on the switch, so in essence the system was still on. Once I stopped the key in the correct off position my drain stopped. Stupid, yet so simple. My not be your issue, but I suggest you check this before you tear into things as it only takes a second.

Mark

[Michael M.]

Re: Severe Battery Drain

Thanks for all of the replies and suggestions, I have isolated the issue to the starter.

When I disconnect the big battery cable from the starter, the draw goes away completely. I completely disconnected the alternator and horn relay with no change in the draw but the starter still connected. So the starter is it? Or not? By disconnecting the large battery cable from the starter, I have completely removed all of the power from the vehicle since the battery cable goes directly to the starter. So, of course there's no draw because the positive cable isn't connected to anything and I am connecting the amp meter between the positive battery post and the positive cable. Now I think I'm confused.

Does this mean that I should merely replace the starter, or does that isolate the issue to the starter circuit? So for instance, I removed all the fuses and the draw remained. Does this rule out the ignition switch? At this point, I am at a loss as to what to do next (other than replace the starter). Thanks for any replies.

[John W.]

Re: Severe Battery Drain

Michael,

Your starter Solenoid has two wires connected. A #2 gauge black wire (big) and a smaller 14 gauge brown wire. Disconnect the 14 gauge brown wire from the solenoid to isolate the rest of the car from the starter. If you still have a current draw it is going to be your solenoid that is the problem. It could be stuck partially closed or just be full of conductive dirt. Could be drawing enough current to heat up the starter motor without really turning it.

The more likely cause is going to be the 14 gauge brown wire because it goes to everything else in the car.

Let us know what you find from that test.

[Michael M.]

Re: Severe Battery Drain

Thamks John, I'll try it. Reconnect big wire from battery and disconnect wires from solenoid. I think there may be a white fabric covered wire on the starter too, I'll just make sure the solenoid is clear of wires.

[John W.]

Re: Severe Battery Drain

Michael,

The big wire on the starter itself should go to the negative side of the battery and maybe a smaller wire from there going to some other ground points. Can't draw any current through there.

The purple and yellow wires on the solenoid come from the starting circuit to cause the solenoid to close providing all of the current needed to turn the starter motor. I don't think either of them could contribute to the current draw you are experiencing.

There aren't that many things that are not protected by a fuse so it has to be one of them.

[Michael M.]

Re: Severe Battery Drain

John, when I disconnect the brown wire off of the large starter lug the draw goes away. The removal of the other small wires from either side of the large lug had no effect, connected or disconnected.

So from your post below, it appears the solenoid is good. Correct? Now what? Should I just follow the brown wire on the wiring diagram and see where it goes and check components? Thanks again for the assistance.

[Michael M.]

Re: Severe Battery Drain

John, I just read your prior post. The battery cable to the starter though is the positive cable and not the negative cable. So now I've finally narrowed the issue, but I'm not quite sure if this means the solenoid is good or bad or if I keep looking.

[Dick W.]

Re: Severe Battery Drain

John, I just read your prior post. The battery cable to the starter though is the positive cable and not the negative cable. So now I've finally narrowed the issue, but I'm not quite sure if this means the solenoid is good or bad or if I keep looking.

If I read your post correctly, you disconnected the body power feed from the starter solenoid. If you did so and you still have a drain of four amps, it has to be the solenoid or the starter. A four amp drain should result in the offending component becoming somewhat warm.

[Michael M.]

Re: Severe Battery Drain

Thanks Dick. The drain disappeared when the brown power wire was disconnected from the starter lug. From your post and John's posts it appears this means the starter is NOT the problem.

So my question is what does this mean to me. I had previously removed all fuses (still a 4 amp draw). Disconnected the alternator (still a 4 amp draw). Disconnected all wires to the horn relay (still a 4 amp draw).

I am truly at a loss. I may have to bring it to a pro, unless you guys have more ideas. I do appreciate all the help.