hey guys. I have been having issues with my battery drain for a few yrs now. when I get a new bat, it will stay charged for maybe a week without starting. over the course of a month that time will go down to overnight then just hrs. So last month I changed from a one wire alt to a 12si and wired it up according to the diagrams here. Put in a new battery and started it the voltmeter reads around 14 running. For the next few weeks it would sit mon-fri and fire right up on the weekends. Now I go out there today and its dead voltmeter read under 10. So I put a test light in series with the neg terminal and the light came on. Pulled every fuse that is present in the block and the light never went out. I'm confused as hell, please help. Ready to put this problem behind me but don't want to pay $$$$ if I don't have to. Thanks for any help.
72 chevelle battery drain.
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I am not the best, or anywhere near it, on electrical issues. But, it sounds like you have a wire in one of the harnesses that has a bare spot or has somehow contacted the firewall, dash, etc. Try to trace them out and look for bare spots, and/or disconnect them one at a time and see what you can find. Maybe leave the test light burning while you check the wiring and watch to see if it goes out. Don't forget to check the harness to the alternator.
There are some really good electrical folks on TC and I expect they will have a better diagnosis to the problem. Good luck with it, and let us know what you find out.
There are some really good electrical folks on TC and I expect they will have a better diagnosis to the problem. Good luck with it, and let us know what you find out.
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no the voltmeter only reads with key in acc or on. On another thing I noticed that might be weird is that my turn signal handle that you turn them on with is real loose. If you touch it with a voltmeter(the actual metal handle coming out of coloumn) it reads 12.5v. Also if you jiggle it around but don't fully engage it it makes a clicking noise that I can hear and feel in the horn relay. Does this sound like a culprit?
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I would disconnect the small gauge black wire that goes from the horn relay, up through the column to the horn contact from the relay,(at the relay end of the wire) at least until time to get the horns working again.
That will keep the horn relay from being energized.
That will keep the horn relay from being energized.
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If you mean the turn signal lever is still lighting the test light with the horn contact wire disconnected from the relay, I would say it's time to pull the wheel and investigate.
Might do the parasitic battery drain test too.
Yeah the horn relay changed a little in 72 and was relocated to the firewall but I think that wire is still a small gauge black wire.
Might do the parasitic battery drain test too.
Yeah the horn relay changed a little in 72 and was relocated to the firewall but I think that wire is still a small gauge black wire.
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2,720 Posts
Key off, doors closed NOTHING on.. after market stereo? Amp not wired correctly?.... I’ve seen 100 times where people wire the trigger lead to the constant B+ = AMP an all the time. Just guessing….
ok went ahead and unhooked the 4 wires from horn relay main power post and reconnect one at a time until it lit again(alt power,1 small guage,1 med gauge, and one thick 10 gauge red).Hooked up alt wire light stayed off, same with the small and med gauge wires.
Then I hooked up the 10 gauge red and the light went on. it even lights if I touch the wire then touch the body, or touch it against any of the other 3 wires. The 2 wires that are not the culprit appear to go to the harness under the brake booster. The culprit wire runs toward pass side along firewall. Havent tracked it yet, OLd alt wire, Starter solenoid,idk?
Then I hooked up the 10 gauge red and the light went on. it even lights if I touch the wire then touch the body, or touch it against any of the other 3 wires. The 2 wires that are not the culprit appear to go to the harness under the brake booster. The culprit wire runs toward pass side along firewall. Havent tracked it yet, OLd alt wire, Starter solenoid,idk?
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Disconnect the one wire alternator and see if it goes out (did you have this problem before you installed it) The harness under the booster goes to the fuse box and that goes to …. Everything 
What did you do to determine the problem goes along the firewall?
EDIT: just some other random thoughts… aftermarket distributor/coil? Also seen where they are inadvertently wired to constant.. not good.
What did you do to determine the problem goes along the firewall?EDIT: just some other random thoughts… aftermarket distributor/coil? Also seen where they are inadvertently wired to constant.. not good.
No one wire alt, got rid of that, have a 12si. I think I found it. It is the wire from the horn relay to the starter solenoid. I have a mini torque. Cant remember brand its been 6-7 yrs. Can I take it to a starter shop for a new solenoid or do I need a new starter. This one is still in good shape otherwise hate to scrap it. Now that I think about it about 2-3 yrs ago my buddy stuck a screwdriver down there and got a big spark, I wonder if that's what did it in.
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2,123 Posts
Factory clock? A stuck factory clock solenoid coil will cause this, too. A fairly common problem on GM mechanical clocks. The clock does NOT have to have been working for the coil contacts to be stuck in the energized position, causing the coil to present a constant load to the battery.
Last one I had with this would drain a brand new battery flat dead in less than two weeks.
Last one I had with this would drain a brand new battery flat dead in less than two weeks.
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Your description got a bit confusing, but I picked this out....
Does the car have (or did it at one time) factory air conditioning? Factory air cars have a high speed blower relay that is hot at all times mounted on the a/c box on the passenger side.
Please elaborate dean because I am new to the wiring dide of this stuff.what I apear to have is 3 wires to the starter. Which I know is normal from doing simple starter changes. Theres the big one from the batt. to the big post on solenoid. Then I have a smaller 12gauge or so and then the 10 gauge from the horn relay to the solenoid. The one from the solenoid to the horn relay is the one that causes the test light in series with neg batt. terminal go off. That is the only thing that has made the light go out.
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