Alternator discharge?

[NINERS1]

Hey guys, need some help, after not starting my truck for a couple days the battery runs down, i have a 71 chevy with a 3 wire alt (100 amp) and have a wire direct from the output on alt to battery (8 guage) could my alt be discharging my battery when its not running? I am electricly challenged!!! lol thanks for your help!! Jim

[Wrenchbender Ret]

Yes. Take the heavy wire off the term & touch it to the term. to see if you get a little spark. If so you have a shorted diode in the alt. I take it it is an internal regulator.

[NINERS1]

Yes it is, take off the bat term and touch the alt term?

[spinem]

false, he has done what i have done, him touching it like that could give a false answer, by doing that it could spark due to a drain on the cab.

Remove every fuse from the truck.
touch the + off the alt to the + on the battery (one strand of wire only... you arent trying to weld here)
If you have a spark, it COULD be bad diodes... diodes make energy go one way (a check valve) thus, ur alt makes energy while running and while not, does nothing.
if the alt is bad, while not running the alt will draw power.... another obvious sigh is heat from the alt even when the truck has not been running for along time.

another test is to remove all fuses, and install a voltmeter in between the + of the batt and the +off the alt. the meter should read 0-0.001......
0.30 is normal draw for a cc vehicle.
/w/ a .30a draw, your batt will be dead in 2 days. GUARANTEED

(my alarm system draws .30 24/7) and dies in 2 days. (duraSUCK..DURALAST)

questions? PM me. i will not be viewing this thread again.
hope this helped

[Bob 68327]

remove your alt and take it to a parts store and have it tested . Eliminate it as the problem then move on . my 2 cents worth too many things could be draining your battery this is a good place to start.

[NINERS1]

thanks guys, found the problem, I had the exciter wire plugged into a non switched circut on my fuse block, was hot all the time!