Just bought a 2005 crew cab with 144000 mile on it. Truck is in great shape. Their is one thing that I can't figure out. It may take one week or two weeks, some times the battery indicater on the dash will move towards High and I hear a noise like a bad bearing. It only last about 5 sec and quits. Like I said it doesn't happen all the time, so cann't troubleshoot. One note, the allternator is not OMG. Haven't had the allternator tested. Hopefully someone has experienced this and can point me in a direction.

 

OMG! you say the alternator isn't OMG...wow (or OMG).

 

It sounds like the voltage regulater which is still in the alternater I believe. do you notice the lights get brighter when it happens. the whining noise I believe is the alternater working at full output sounds almost like a supercharger. if it only does it right after a cold start it could be a weak battery.bubbabud

 

Bubba, Hasn't happened at night yet. Has never done it after a cold start.

Have noticed that dash lights and overhead light pulses with the motor at ideal, at speed it stops pulseing.

 

Your question has already been answered in this thread: https://www.f150forum.com/f4/battery...2005-a-129717/