Ill try to give as much info as i can to descibe the problem. Main problem, battery keeps going dead. Went through 2 alternators, first battery was an optimum red top. Returned it, second battery now is a deep cell optimum yellow top. Got about 5 cranks and now is completely dead.

motor 383

-Am running 2 16inch zirgo electric fans @ 3000cfm each. 1 is on a relay to turn on at 158 and is wired to the accessory box. I unplug it everytime i shut the car off. Second fan is ran to a switch which runs straight to the battery with a built in fuse.
-Stock intank fuel pump is wired to a switch, which plugs into the accessory box.
-Tach is getting power straight from the battery, little 15$ sunpro tach i bought to get the car started.
- Am jumping the neutral safety switch with a wire, havent hooked up to the shifter yet. Not sure if this matters or not.

The wire from the back of the alternator is going to the positive of the battery. Thickness of that wire doesnt seem all that big. I compared it to my fathers 2008 silverado and his alt wire is as thick as the battery cables. Is it possible the wire is too small?

Car was a v6, all the wires we did not need ( 383 carb now ) we cut and wrapped in electrical tape. That shouldnt be an issue correct? Am stumped.

 

Well if all you have is one wire going from the alternator to the battery and your using a stock alternator that is your problem right there. These alternators require a few wires to function. Off the top of my head they need one to sense the battery voltage, one to supply 12 v, and another to charge the battery. The sensing wire allows the alternator to adjust itself to output the correct voltage. The 12 v supply is needed because as strange as it sounds the alternator needs power to generate power. The reason is the alternator doesn’t use a permanent magnet to generate electricity it uses an electromagnet. No magnetic field no power generated.

 

does this mean if on a hill with a dead batt you cant roll start it?

 

The problem ended up being the brown wire on the alternator plug. Believe its for the indicator bulb. I cut the brown wire and my battery went from 8v to 14.5.

 

Yes thats exactly what I'm saying. See that trick works for stick shift cars especially older ones because a lot of times when you have a "dead battery" its not really dead per say just not powerful enough to start the car on its own. It takes a lot of power to crank it over not so much to actually run it. See on an old car with mechanical fuel pumps and what not all they need is enough power to power the ignition system. Today with electric fuel pumps and all the electronics its not quite so forgiving. However in either case if the battery was truely completely dead or removed all together you would not be able to push start it.