Used the search function but did not help.

2000 F-350 7.3 Diesel

Here are the symptoms:

Using 2 Optima batteries and a refurbished alternator from NAPA

- Batteries die overnight, so I unplug the negative cable each time I park it
- Batteries smoke and looks like acid is boiling.
- Batteries are around 12.5V when the truck is on


Any ideas?

Thank You in advance

 

might want to check your voltage regulator

 

Looks like you need another "new " alternator .. Get a motorcraft this time ...

 

It sounds like you are MASSIVELY overcharging your batteries. Obviously, smoking batteries is a VERY bad thing. You have a couple options; one of them is NOT waiting!

1. Buy another replacement alternator
2. If you have your stocker, get it rebuilt at a local shop
3. Buy a better alternator

For #3, Rick mentioned a Motorcraft (i.e. OEM). I bought a 200A replacement off Ebay from Eagle Auto Electric. If you get an upgraded alternator be sure to get a thick wire (4ga recommended) for the power supply line to your alternator.

 

I would suggest getting rid of the optima batteries, from my experience some of them don't like being charged above 13-13.5v