Battery Light

[decableguy2000]

03 5.4 xlt non nav, battery light on after alternator change. Old alt had no output, new on has 13.6 and is charging battery. What to check next or swap alt out? Starts fine and runs well battery comes on approx 30 sec after start up and stays on

 

[whtbronco]

If the Malfunction Indicator Lamp is on there is likely a trouble code as well. Scanning it with an OBDII scanner would be a good place to start.

I will say when my original alternator failed I had to take what the local Advance had in stock. It lasted almost 2 weeks and while rolling down the interstate late at night every light went out. It had a broken wire inside. I've had a number of faulty yet brand new parts, so just because it's new or reman'd doesn't mean it's good.

 

[decableguy2000]

Ended up tracking down a Motorcraft Alternator. No more issues. 110amp alternator only used 03-04.