Need help fast, alternator and charging system

[Justin35ll]

I have a drift event tomorrow at noon.
A few weeks ago I was at an event and my alternator pivot bolt fell out causing my belt to become loose and squeek, I drove home from the event like this as it was my only option.
I got into town and my radio starts flickering on and off and the car starts running like s***.
Okay well I figure the battery wasn't getting a good charge and it killed the battery.

Now i charged the battery and start the car, but i'm only reading 12.5v at the battery when it's running.
I already tried swapping alternators and that wasn't it.
I have the dash out right now because i was getting a cage welded in.
I just have no idea any one have anything to look for or try? Is there a wire or connection in the dash I'm missing?

[OutToWinPAHC]

Does the voltage go up as you increase throttle? Maybe just pull the alt and have it tested, the regulator is internal.

[PhopsonNY]

Only things can be

The wire - check wire to battery and alt ground are not fried
The alternator - check as suggested above that your new alternator is not bad too
Multimeter - not reading properly
Short in system - maybe while driving with faulty system, you fried something which is now shorted and adding a load to your system.

Good luck and let us know what you find out.

[costa_rican13]

Im having a similar problem except when i turn the igntion on the dash lights come on but when i go to crank they just shut off..and no start or even clicking off the starter

[Justin35ll]

Yeah as of right now I'm not sure. When I start the car up usually the battery will read about 12.5v running. Then i'll tap the gas a little to rev it up and it jumps up to 13.5 - 14.8 and it will stay there. I drove the event and car was running fine

and sound likes a dead battery costa

[costa_rican13]

im hoping so... cause i've been down for 2 days. but i work at autozone so im about to get hooked up with a nice battery for cheap cheap. thanks. is the battery in trunk?? maybe you have a burnt wire in the floor?? umm fuse check?? as far as the voltages shouldnt the reading jump up since the brushes are spinning faster?

[PhopsonNY]

Justin,
Those are symptoms of a faulty alternator... was the replacement alternator new?
If it does that consistently, then it is on its way out...

If you have an interior voltmeter, it would be interesting to see what happens to your voltage over a long drive, as things heat up, your alt may be putting out less and you would not know it.

[OutToWinPAHC]

Yeah as of right now I'm not sure. When I start the car up usually the battery will read about 12.5v running. Then i'll tap the gas a little to rev it up and it jumps up to 13.5 - 14.8 and it will stay there. I drove the event and car was running fine

and sound likes a dead battery costa

This is normal