P1397 Ford -

Question

Truck starts drives a little then dies. When you start it if you turn the headlights on it dies. Guauges and dash lights not functioning and then they will work. Started truck this morning and everything was fine while it was cold. Before this happened I noticed power surges every once in a while while driving the speedometer would flicker an sometimes go right to zero and stay there for some time. Sometimes the engine would stutter when having this power surge. When truck was parked and on high idle when this power surge would occur it would cut out the high idle and then when goes back to normal high idle comes back up. I replaced the alternator same thing though. Would a bad ficm cause those problems or maybe a bad battery? I cleaned all the posts everything is good but I havnt load tested the batteries. Or would it be the ecm is having problems or anything else it could be?

Answer 1

I would check the battery first. 

also there is a upper and lower generator (alternator) for this car, if the voltage is over and under spec they both have to be placed.