Hey guys just wanted to share an experience I just had with my 03 Expedition 2WD 4.6L XLT. My wife drives it and she told me the battery light would come on and then she would look back down and it was off again. Then twice with her and once when I was driving it would just die, and I don't mean sputter and miss and die I mean die like someone reached over and turned the switch off ( I was even accelerating up an on-ramp).

So I kept it one day while I was off from work and drove it around. When the light came on I used a voltmeter to measure the voltage at battery and it was 12.35 volts which is too low with it running. When the light went off I measured 13.79 which I think is ok since it is close to 14V. So I took it to an Autozone and had them check the alternator and the light was not on when he checked it and it still failed the output test. So I am thinking it is an alternator and I go home pull the alt that evening take it to the parts store and pay $200 for a re-manufactured alt. I put it on the next morning and after I get it replaced I start up the vehicle and the battery light stays on constantly. I drive it back to the store and they check the alternator and it shows no output from the alternator. The guy says to check the fusible link and the wires from the plug on the alternator or they can swap out the alternator again. So I take it back home and tear into it again and find that the fusible links are fine (they are the ones that are between the positive post of the battery and the single stud on top of the alternator) but when I follow the wires from the alternator they go into the wiring harness and then run along with the large gauge wire of fusible links then split back out just before the fusible link and go over to a connector just below the battery tray and this small wiring harness had laid on top of AC line/tube and it had worn through the insulation of the brown wire with a pink tracer and the wire was no longer making any connection. I unwrapped this and spliced it back together and now the light is off and I am thinking that I spent $200 on an alternator that I did not need. I think that when the light was off then the tubing of the AC was completing the circuit and when it was on it was vibrating and not completing the circuit. I hope this helps someone else from spending $200 unnecessarily.

 

Like this?: https://www.ford-trucks.com/forums/9...ml#post9213727

 

Yeah. Sorry, I really did search through the forums trying to avoid duplicates before I posted. I think that post was so far down in tge thread that I probably skimmed over it.