ok, this one has me boggled......

when I got my '78 (L82 with AC) the end of Feb and had it flatbedded home the first thing I did was go out and buy a new battery - the car didn't have one at all.
It sat untouched for about 2 months while i pulled the motor, cleaned and refinished everything than put the motor back in.
since I got the car running the battery has gone dead 5 or 6 times.

Ok, I figure it's one of two problems:
1. charging system not working correctly
2. a drain somewhere in the system.

I checked the charging system and it's fine. Good output from the alternator and good voltage back at the battery to charge it. No problem there.
That leaves a system drain ( of course, the HARD one to deal with - it can never be easy like the alt isn't working and i can have that swapped out in 10 minutes!)
I didn't get a chance to check thru the system to try to find the drain before taking the car into the paint shop (where the battery has already died 2 or 3 times in the 3 weeks it's been there!).

Wet to check on the car today and the painter tells me he thinks he found the battery drain issue purley by chance.
He had been sitting in the car, the shop was very quiet and he hears a very faint whirling sound. Turns out it was the climate control blower fan running slowly. The problem is the car was off and the key was out of the ignition!!
Moving the fan speed selection switch didn't make a different but he found that the top slide controle (the one that selects MAX AC, AC, HEAT, etc) had to be moved all the way to the left to the OFF position to get the blower fan to shut down.
WHY would the blower fan possibly be running with the car off??
This has to be the drain on the system that is killing my battery but I'm not even sure how to go about fixing something that I can't figure out how it could be broken. But broken it must be as the blower fan shouldn't be running with the car off, let alone with the key out of the ignition switch.
Maybe a relay gone bad and shorted out to show constant live power innstead of switched power on the blower??

 

I think you answered your own question. Start at ign switch, orange wire goes to fuse block accessory, fused comes out brown to fan switch,out yellow to resistor, out orange back to switch, out orange to blower motor. Shouldn't be a relay anywhere.

Try one of these until you sort it out. About 7 bucks at Northern Supply. They make them with a small tag wire for computer controlled cars as well. I use them on all vehicles all the time. Very convenient.

 

Sounds like Bubba might have been at work there Barry. The fan circuit is on the switched side of things, or at least is supposed to be.

 

noonie

thanks for the wiring info - that will be a big help as i check thru the system when I get the car back.

As for the battery cutoff, I already plan on getting one just haven't gotten around to it yet. Everything is on hold anyway until the car is out of the paintshop which hopefully will be the end of next week.

 

yeah, the key word here is SUPPOSED to be....

or maybe the key word was BUBBA??

amazing how Bubba can be found even on a less than 10,000 mile car!

 

Barry

This should turn it off.

I changed low to off a long time ago & have posted many times how to do it.
Blower A/C Vent
Low to Off
Disconnect connector at resistor box under hood pass. side near high blower relay & bend down the connector to dk. brown wire & reconnect.

 

Ganey

thanks for the suggestion but if possible I want to try to find and fix the issue without modifying the way the system is suppose to work normally.
even with the blower in "low" it shouldn't be coming on at all with the car off and the key in the "off" position.
there is a wire that is on a constant hot that should be hooked to a switched hot lead instead I'd imagine. That's the only thing that makes sense to me.

 

Barry

Yes, that's what I expected. That's reversible. I don't type. The point was the blower can be disconnected for now & secondly if that worked then the problem is most likely that power is connnected to the brown wire all the time. There are other possibilities - checking for wiring changes at the blower or a pic. of the blower wiring could help. It's possible that power is coming from the hi blower relay & the blower is worn out & running slow from being on. That would put a serious drain on the bat.

 

I got you Ganey.

I'll have to check things out and if needed I'll take some pics and post them when the car gets out of the paintshop. It should be done by the end of next week.
That's when I'll be able to start digging into the problem.