I have a draw on the battery on my 85 Toyota pickup it kills a fully charged battery in about 2 hours... Ive put a volt tester between the disconnected positive battery cable and the positive battery post and its pulling over 11 volts with everything off.. Ive put a test light between the positive battery cable and the battery terminal and I have a steady light and I pulled each fuse one at a time and the light never went off ive isolated the short in the alternator circuit if I disconnect the alternator wiring harness from the main harness the draw goes away ive replaced the alternator did not help, im wondering if the harness is bad I inspected the wires and they are worn but dont look that bad sone cracking so I separated all the wires and re connected the alternator wire to the main harness again mega draw came back very stumped please help

 

Might be a shorted diode in the alternator. Should be able to pull it and have it tested at a good shop.

 

Ive replaced the alternator just today and as soon as I hook up the alternator harness the draw is back I thought for sure it was the alternator

 

Might try disconnecting the alternator harness and test pin to pin for any shorts with an ohm meter (disconnect the battery while testing out the harness to avoid damaging the meter). If any pins show connections between them, check out the FSM wiring diagram and see if they should or not.

 

Ok thanks ill try that it seems to be isolated to that harness why else would the draw drop when disconnecting the alternator harness unless completing the circut is cauing the draw? Im not sure thankyou

 

Same thing I just told the other guy, Check for corrosion on the terminal. Older Toyotas are super temperamental about that. replace the terminal if there's even the smallest amount of corrosion. Let me know if that fixes it.

 

Found the issue the alternator wiring harness was shorted bad replace the harness from a junked out truck and it fixed the problem thanks guys for the advise