I bought a new battery today and at first it was reading 14.0 volts and now it's at 13.2. Is my alternator going out?

 

An old school way of testing is to remove the positive cable to the battery while the truck is running, if the truck dies then you probably have a bad alternator. you may want to research it though before trying.

 

Thanks and yea I'll do that before I try anything!

 

BTW, autozone will test it for free.

 

Thanks for the heads up

 

Put a meter on it and crank the truck over. Battery should not drop below 10 volts while starting (unless if it is extremely cold out). Once its running, the meter should read somewhere around 14-14.5 volts.