The battery light on my My '03 Expy 5.4 came on a couple days ago and had what appeared to be a bad alternator as originally diagnosed yesterday by the local Ford QualityCare center. This was a 2 month old NAPA alternator I installed. Since it was still under NAPA warranty, I replaced it myself.

Before replacement, the light would come on at idle, and go off above 1K rpm. After I replaced the alternator last night, the battery light stayed on all the time.

Went back to the Ford place and they did further diagnosis, and it looks like the wiring harness from the alternator has a broken wire. The alternator is charging, but the computer doesn't know it, hence the battery light.

Harness is ~$40, but they want $90 to install and $90 to "reprogram the computer". They said I could install the harness myself and save $90, but computer "had" to be reprogrammed.

I put my Actron code scanner on it, and there are no codes.

Is this reprogramming really necessary??? If it isn't, I can buy the harness, install it and a $250 repair becomes a lot cheaper!

Thanks,

John

 

Anyone know whether reprogramming is needed or not?? Hoping to find out before the repair places calls to tell me the parts in.

Thanks,

John