My 68 BB has had an electrical drain ever since I bought it several years ago.  I had installed a cut off switch, but I finally thought I better deal with this.  So, this is what I did!

Pulled all the fuses and checked for a voltage drain between the neg post of the battery and the neg cable.  Yep, even after pulling the fuses, showed a 5.9 amp draw.  So, I disconnected the alternator wires, yep, still a 5.9 amp draw.  Disconnected the voltage regulator, yep, still a 5.9 amp draw!  I'm at the end of my rope here folks.  What else could it be?  It isn't the wiper overide switch.  I'm trying to think about what isn't fused?  Starter, ignition switch?????  Any ideas out there where to look next?  Really could use some help on this one.

Thanks

Mark

 

Well Mark,I'll take a stab at this one but I hate to say it probably is a matter of patience and perserverance at this point. You've done everything anyone would have up to this point.Just continue on disconnecting and I would bet you will find the problem.You have already eliminated many circuits.I don't have the 68 schematic which would help me isolate what is not fused.It is possible that it is not a component,but a slightly chafed wire touching ground after a component.Try eliminating large areas of the harness by disconnecting harness plugs until the draw disappears.I don't have an idea on anything specific.You pulled the fuses,now try pulling relays,flashers,etc.,anything you can disconnect to narrow it down.Sorry,it is the best I can do until you narrow it down.Maybe one of our super techs has seen this before and can help more than I have.Good Luck.

A wiring diagram would help, but since I don't have one for a '68, I'll venture a few guesses!

On the driver side, inner fenderwell, there is a horn relay. The weird thing about that is, it is also one of the main terminal/connections for several other "hot" circuits. It is fed 12v from the large terminal of the starter, through a fuse-link. See if the drain goes away when you take the wires off the horn relay. This will narrow down the search to those systems powered off of that terminal.

I don't see a key-switch for the fact. alarm on the back of your car, so I assume you don't have that, so that's not the drain. (The relay for the alarm can draw power off the batt., even if it's not armed.)

The only things I can think of that are 'hot' at all times are the horn relay, the alt. gauge, clock, & lights.(interior, headlites,& brake lites)
I think the wiper motor has 12v all the time, too. It is controlled by ground, but I'm not 100% sure on that. A wiring diagram would really help out here.

There is also a slim chance that the ign. switch is giving out voltage when it shouldn't be, but pulling all of the fuses would eliminate that as the drain.

Maybe this gives you some new ideas to try.



btw.....I know this is gonna be a stupid question, but did you have the door open when you checked the drain? Just axin! Adams' Apple38589.7822685185

OK, call me an idiot, but yes, I had the door open when I checked.  So I checked with the door closed.  Behold it still had a drain.  So I disconnected the horn relay.  Yes, that did the trick.  Now at least I know where to start looking.  Horn hasn't worked, so maybe the button is down and causing the drain.

Thanks guys for getting me back on track.  Not totally solved yet, but like I said, back on track.

Mark

[QUOTE=corvette427]OK, call me an idiot, but yes, I had the door open when I checked.  So I checked with the door closed.  Behold it still had a drain.  So I disconnected the horn relay.  Yes, that did the trick.  Now at least I know where to start looking.  Horn hasn't worked, so maybe the button is down and causing the drain.

Thanks guys for getting me back on track.  Not totally solved yet, but like I said, back on track.

Mark
[/QUOTE]
Did you ever find the source of your drain?
My 79 is draining and I'm about to hunt for the source.
Adam38884.2553356482

[QUOTE=corvette427]OK, call me an idiot, but yes, I had the door open when I checked.  So I checked with the door closed.  Behold it still had a drain.  So I disconnected the horn relay.  Yes, that did the trick.  Now at least I know where to start looking.  Horn hasn't worked, so maybe the button is down and causing the drain.

Thanks guys for getting me back on track.  Not totally solved yet, but like I said, back on track.

Mark
[/QUOTE]

Look under the horn button on the steering wheel ..mine was messed up in there.  Drawing almost 6amps is a pretty good drain it should be obvious when you see it.

Alan

Alan

Battery drains are witch hunts at best. I have had one on my '59 Biscayne for 10 years I can't find and I have done all the tests. If anyone figgers out a concrete method of finding it please let me know....

Dave

I recently had a huge drain on my 74 caused by a starter wire fire. One of the wires got fused to another  It was a b*tch to discover. The short was between the starter and the coil area of the motor.