ok so last weekend i took my jeep our to Mojave road and it did great, until day 3. halfway through the day my volts went from 14 to 12 and by the time i hit the freeway my volts were a little above 9 until my gauges just went dead. i pulled over and we checked wires and such then needed a jump to get back going but it ran like there was a miss in the motor (FI?) i replaced the battery and alternator. it has new car, rotor, spark plugs, and wires. thoughts anyone? im stumped...

on a side note right after i got back i removed the alternator and had it tested at autozone. it tested good. had them check the battery and it was bad. put a new battery in and the old alternator and it did the same thing. drove back to have my charging system tested. alternator tested bad at 12 volts not 14. so i put a new alternator in. still doing the same thing. maybe loose ground to the alternator? fuse?

 

Refresh all your grounds and battery cables, no matter what they "look" like.

 

it was a blown fuse haha finally got around to checking

 

See my comments elsewhere on this sort of "Test" - they check output voltage at a very low current, and it is the CURRENT that needs to be tested at nominal voltage (those benches usually draw 1-1.5A @ 12VDC, which isn't enough to run a good flashlight.)

Find my writeup on how to do a "driveway" test that will give you rather better results than the chain stores - it's not a quantitative test (it won't give you hard numbers,) but it's a good qualitative test (it will give you a "state of everything" to help you make a more informed decision or diagnosis.)

 

Here's the write-up

https://www.cherokeeforum.com/f2/bat...or-test-78125/