I found my battery draw...sort of.

Sycostang67 · #1 (**permalink**) 10-22-2009, 07:35 PM

Still playing with my 86. I let it sit over night and the battery was dead. It's a brand new 1000CA battery. I used the test light between the negative battery terminal and cable. I popped out all the fuses but got nothing. When I disconnected the fuse link from the solenoid, then the light shut off. Whats on the other end of this wire thats sucking my battery dry?

I replaced this fuse link earlier, hence the spade terminal in case I had to replace it again. I am using a fusible link.

bashby · #2 (**permalink**) 10-22-2009, 08:50 PM

Alternator maybe? follow the wires and see if thats where they go... It's not uncommon for an alternator to short and create a draw

Sycostang67 · #3 (**permalink**) 10-23-2009, 02:24 AM

I hope not, the alternator is new as well.

Eddiec1564 · #4 (**permalink**) 10-23-2009, 04:28 PM

Pull off the alt wire and see if the draw is present. I got a new alternator once , had to take it back week later... and had to fight their "no returns on electrical parts" as it killed the battery sitting over night, a bad diode will do it everytime. But the stupid thing would check fine on the tester, till I said to hook a battery to it with the test light in line...... never went back to those numnutz 3 stooges!

Sycostang67 · #5 (**permalink**) 10-26-2009, 01:29 PM

I guess I will pull it and have it tested. Our bench tester can detect a bad diode. It would suck becasue the alternator is new, but the PO bought it so no warranty return for me. I do have an older one I may be able to use if it's bad though.

Sycostang67 · #6 (**permalink**) 11-03-2009, 02:05 AM

I tested the alternator and it failed every test. It's internally regulated and was putting out 30 amps, which explains why the battery guage would peg every time I touched the gas pedal. Internally regulated also means really expensive, as in $100 for a dang alternator. I'll get it installed tomorrow and hopefully will have solved one problem.

Eddiec1564 · #7 (**permalink**) 11-03-2009, 03:40 PM

Yep, not cheap anymore, the alt for my 89 f250 was $90 and that was not fun changing it in a parking lot! Going to grab a few alts from the jy for $15 each just in case!

Sycostang67 · #8 (**permalink**) 11-04-2009, 02:39 AM

I like how alternators for my mustang are still $20. lol

I got the new alternator installed which was a PITA since somehow the entire mounting bracket managed to move enough to not let the bolt thread into the block. It's weird since I never loosened the bracket, I tried moving it but couldn't so I had to loosen it to get the bolt in.

Regardless, the test light trick shows I no longer have a battery draw. My battery guage still reads heavy on the charge side though and goes up slightly with an rpm increase, but not as much as before. The needle only goes halfway to the "C" instead of all the way across the guage. I left the battery hooked up tonight and I will try and start it tomorrow.