So after much frustration I have been dealing with for 2 weeks electrical charging system issues. Need advice and thoughts on this dog. 2 weeks ago while driving home pulling a trailer I noticed the ABS light come on. I have seen and fixed this problem with other F250s in the past, as you may have guessed I lost the alternator. I replaced it with a AutoZone, which I also know is a crappy reman., however the truck cranked and got me home. Next problem, I notice after sitting for two days without driving that the batterys where dead. One battery showed 6-7 volts on test with the cables unhooked and would not hold charge, second battery had 10v and after charge held 12ish volts. replaced bad battery. Cranked truck and ran for 5 days of driving no problems. I parked and let it sit for 1 day, now back to square one. I jumped the truck and got it running. After testing it reported at the alternator a output of high 12 to low 13v at the back of the alternator. Not enough so I drive up to the "Zone" have the manager pull test on the alternator. No good, so I replace it in the parking lot, he checks it again and says the same thing No good. I say screw it and come home. Now Im trying to get this thing on the road cause I want to sell it next week I have 3 buyers and a un running truck. Need help and thoughts on the problem. Heres the current stats as she sits in the yard now.


Battery #1- Holding 11.96 volts
Battery #2- Holding 11.94 volts

Truck running at the back of the alternator its putting out 12.76.

Ideas? Fuses, relay, bad ground? Yikes, someone throw me a bone and lets get this thing sold!

Thanks!

 

Bad cable. You should of replaced both batteries. The old
one will kill the system. Take each battery out and have them BOTH
tested for load and with a hydrometer. Next thing will be check the cables
while the batteries are being charged. Clean all connections block side and
on the batteries. Make sure you also do the ground points on the frame
and engine. while you have it unhooked check the resistance of each cable.
Also check the small plug that goes to the back of the alt and trace it back
to make sure it's good. Did the Autozone guy test the alt on the truck or
the test stand. It needs to be run on the test stand to prove that it
really is bad. here is an odd question for you. When you turn the key on
and all the lights come on to prove that they work does the ALT/BATTERY
light come on? If not be sure to replace that lamp. The thing was that they
used to ground the alt by way of that light. Even if it was not lit it
still needed to be there. Most likely they have change that but worth checking.
You have your homework.
Please let me know whet you find.

Sean and one for you in case you need