EliteCamaro94

So for the past few weeks after i had my trans built and got it back the car was running great, now i went out to start her up after sitting for a few days and the battery is dead. I charged it up and it started but as the car was running the volt gauge was going up and down as if the battery was dying while the cars running. It has a new battery in it and like i said the car was running great for the past couple weeks since i got it back from the trans guy. Any info would be greatly appreciated.

DisasterFormula

iTrader: (1)

Sounds like a dying alternator. Check to make sure the connections are tight, no corrosion, and that the pigtail is plugged in well, the wire off it isn't cut or melted. Check your grounds for corrosion and tightness. It's entirely possible that Snuffy didn't snug a bolt that grounds the engine down good and tight.

F0x Slaughter

Put a multimeter on the battery it should read over 13 when running. That will tell you if the alternator is working.

EliteCamaro94

where can i get a multimeter?

SS RRR

iTrader: (2)

Any auto parts store or Sears. Alternator should not fluctuate at all and should read a steady ~14.5 volts (can't remember exact value) when the car is running.

EliteCamaro94

yeah ive only gone by the volt gauge in the car but the needle goes up and down and you can hear the car sound like its not getting full power. After i charge the battery and start the car if i go out like 2hrs later it wont start anymore

DisasterFormula

iTrader: (1)

Hmm. Might be time to go get the battery tested.

EliteCamaro94

battery is brand new and is the second one ive put in, in the past 2 months. Im thinkin its the alternator

Alex94TAGT

I'd test the alternator, as well as test for parasitic drain with the car off -- should be no more than 20~30 mA (0.020~0.030 Amps) after the retained accessory power system shuts off. Can elaborate if you wish.

[Edit] Kinda already been mentioned, but definitely check the electrical connector on the back of the alternator. That's the exciter wire which basically tells the alternator when to charge. The female pin in my connector broke and caused a lot of voltage fluctuations due to poor contact -- until I found the problem.

F0x Slaughter

If you get one with an Amp clamp all you have to do is clamp it over the positive cable on the alternator and it will tell you how many amps its kicking out, IE its working.

blakez28

iTrader: (6)

Btw make sure the ground for the alternator is plugged in..I forgot this on my car once.
Try getting a new alternator they're not crazy expensive, or see if you can swap with a buddy that has an LT1 real quick.