So, I have had a frustrating problem for the last couple of years. In summary, it's an 87 Monte Carlo SS, 383 stroker, with a 105 amp alternator. I'll get a brand new Optima battery, the car will start once or twice and the battery is dead/fried and has to be replaced under warranty. So the car keeps eating batteries and I have replaced the alternator three times now. I'm unsure how to troubleshoot this if anyone has some guides, flow charts, or ideas? Thank you in advance.

 

Try this, after the car is started, pull the + cable off the battery, does it die?

 

Check the cranking amps of your Starter. (replace if excessive)
Size Battery for that demand.
Check Cables and increase size if draw is large (600+ amps)
Check clean ALL connections.
Double strap grounds on Engine. (battery ground/frame straps)