I purchased my first truck last year in September and of course it is a Ford F-150. That fall I had to replace the battery, and then in December the alternator. Not just once, but I have replaced it several times. The first one was your typical duralast alternator which lasted about 3 months. The next one was a duralast gold and it lasted 8 months. When two days ago I had to swap it out with another brand new duralast gold because the battery light came on, and it was reading low output. If you're sitting in the cab you can watch the headlights flicker, the dash lights, and any other lights. Also, you can watch my RPM's fluctuate rapidly between 500 and 1000 RPM's when idling in park. Any assistance would be greatly appreciated!

 

I could be way off base but have you done the procedure to reprogram the PCM after you install a new battery? I would say there's a 1% chance that that's why they're failing, but I'm no mechanic.

 

Thanks, I'll have to give it a try tomorrow. What is your opinion on it being related to my fuel? Such as my fuel filter, or fuel pump? I have also read a few posts elsewhere about IAC's.