Need a little alternator help.

Black Bear

Black Bear

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Mar 21, 2005
Location
Raleigh, NC
I have been having charging issues with my Toyota. The original system would charge, but it was not charging very well. New atl, voltage regulator later still the same problem. So, I decided to do the GM 3 wire upgrade. I got it mounted, and wired. It charges to 13.8 at idle, which is fine, but now i have a parasitic draw. This is how i have it wired up.. The Bat terminal goes to the battery with a 4g wire. The #1 terminal goes to switched 12v, the L wire of the old atl harness, and the #2 terminal goes to the Bat terminal. I checked the voltage at the battery, its at 11.72v. an hour later im at 11.70v. There wasnt an issue with a parasitic draw before the upgrade, so something is wrong with the alternator or my wiring. Any help would be great.
 
if your battery is only @ 11.7 your battery is probably on the way out, probably from previous alt.. unhook your ground and check voltage is it still at 11.7 or does it jump up past 12 if it does then ya you have a good draw. hook cable back up then turn your lights, blower motor, radio anything else you can find on with in reason and see how low the voltage drops. If battery drops immediatly low below 11v battery is no count.
 
ooops you posted while I was gone....no increase with ground removed = no parasitic draw...
 
disconnect ground from battery and put a test light between battery and ground, if the light is bright like 12 volts bright you have a drain, if it is a very weak light normal drain, if its a bright light start unplugging stuff until light goes out. start with alt. b/c you just messed with it. then start pulling fuses one at a time to track down which circuit it is in. start checking components in said circuit then start chasing wires. and if you can't figure it out you can always bring it to me.
 
nothing from the test light.. and im back to 11.70v, thats good..
So why do i get a very faint spark when i connect the positive cable to the battery?
I wired everything up last night, but I wired it wrong, I did not have switched 12v to the alt, it was a non-switched 12v, and this morning the battery was dead (go figure).. I charged the battery some, and corrected my wiring issue, and tested this afternoon.
Maybe there isnt an issue, and im over analyzing it.
 
ya if there was no light with test light then no drain currently. just charge your battery on a slow charge 2amp for a day or 2 to revive it. the spark when connecting positive cable is a clue to a drain, but there is a small drain, ECU, radio circuits, you really should have had a very dim light on the test light whe doing the draw test.
 
ok i suggest you charge the battery all the way up with out anything hooked up and I will come get my battery back and give you yours so you can kill yours :)
 
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