Not sure what my problem is? Need HELP!!

[super72swb]

I cant leave neg battery cable hooked up will drain battery over night! Now I drove truck to work about 55 miles one-way! Driving back at night time lights went to surging bright to dim then just dim! Pulled over to see maybe loose wire then wont start,battery totally dead, jump start drove to walmart bought battery started right up to get home! Alternator 13.4 volts lights on 12.2 volts! Alternator has wire coming out of top connector to back of alternator and voltage regulator has only red wire hooked up! Blue and white? Brown? or do i even need regulator?? Voltage on regulator match voltage on alt? Oh battery got so low truck missing cause it has HEI!! Bought truck this way and want to make it a driver! If any ideals sure could use the help!!

[fixit-p]

Sounds like you have a short try hooking up a test light between batt neg and cable (series) Where are you getting you voltage readings from (direct from batt pos term. or elswhere) It also sounds like someone installed a internal reg alt if so the wire from the top of the alt which you say goes to the back of the alt should actually go to your main buss feed. Which on our trucks is where the big red wires are spliced and soldered near the left front marker light. the lone wire on your reg. also terminates at this splice run that to the # 2 wire on the alt plug that way the alt maintains peak voltage there and not at the back of the alternator.

[VetteVet]

Take the red wire off the voltage regulator. If your alternator has the plug on the top it has an internal regulator. You can just tape off the red wire or run it to the alternator like Fixit said. Do you have a alternator charging light or a battery gauge in your dash panel?
Take a look at this thread and follow the instructions in it.
http://67-72chevytrucks.com/vboard/s...d.php?t=119379

[super72swb]

Thanks for the info! I will take a look tomorrow and that is exactly what I needed! Hopefully that will fix it!!!