my dads truck has a prob. basically he has a newer battery (within a year old) not sure what kind it is. his battery will go dead after he turns the parking lights on or something similar. the truck wont start back up. after he jumpstarts it and shuts it back off it will fire right back up. took both battery and alternator to parts store for their tests, said they were good. any ideas what the problem is? we were thinking voltage regulator.

 

Check all the power and ground cables.

 

im pretty sure he woulda done that. anyone have any idea how to test the voltage regulator?

 

The voltage regulator is integral to the alternator. It is checked when tested at the parts store.
Sounds more likely that there is a bad cell in the battery , even though it may have tested OK.

 

id take the alt to a diffrent store and test it.

 

my thinking was the voltage regulator could have overcharged the battery causing the battery to wear out more quickly.

 

the best way to test it is useing a volt meter and put it on about 20 dc. have the motor running and put the postive side tester on the hot side of the battery and the neg tester on the neg side. if it about 14 volts its to much.

 

thanks man. ill let him know.