Help!!! I have an 04 F250 that looses all electrical power while driving. It does NOT loose a charge when parked. I can recharge both batteries and it will be fine for about 4 days. Then once again the ABS light comes on, then the dash gages go out, then the odometer goes out.....then it dies!!

Have been thru multiple batteries and alternators! It is NOT these two items!!

Please someone help me!!

 

Truck is a 6.0 PSD. Truck will run with both batteries disconnected.

 

Have you checked your b+ wire from the alt to the batteries?

 

No...tell me where and how!

 

Do you have access to a volt meter or ohm meter? Theres a big thick red wire going from the alt to the passenger side +batter terminal. (Note circuit MUST BE disconnected to perform this test aka isolated).Ohm meter - measure the resistance of that wire from those to points it should be almost nothing, less then .4 ohms. (Note circuit MUST BE connected and live to perform this test) Volt meter - Start the truck up and measure between the 2 same points again, should also be almost nothing. Less then .5 volts If either readings are high replace the wire, kinda sucks its part of the main engine harness so I hope thats not it.

P.S. I'd also run the same tests on your battery cables

 

Rant both tests. .3 ohms resistance and .1 volt. How do you perform the same tests on the battery cables?

 

Connect the meter leads between both positive terminals, the long red wire that connects the two batteries. You could try and test your ground wires as well but that will be kind of difficult.

Are there any codes? Have you load tested the batteries and charging system?

 

Were the alternators testing bad? Do you have twin alts?

Sounds like a ground issue, but that is hard to guess over the computer.

Adrianspeeder

 

Single altenator that tests good. Changed out CD player that had jammed with a disc (this should have nothing to do with it!!) and also removed Egde Procducts "Juice" chip. Noticed the previous genius owner install the EGT sensor in the turbo intake and not the exhaust!!! So far no problems after 7 days (best so far!) Don't know why any of this would fix this but if it does I will not complain!

 

LOL! Does the problem get worse when it is wet outside? Could be a leaky windshield = wet GEM.