On Tuesday, April 26, 2016 at 4:41:10 PM UTC-5, Steve W. wrote:
> Michael wrote:
> > Or something else?
> >
> > 2003 F150 8 cyl. 5.4 L
> >
> > Driving home, the red battery ion appeared in the dash. I didn't
> > really notice any problems with how it drove and I made it home ok.
> >
> > Driving back (20 minutes), I really didn't notice anything but the
> > ABS and red battery icon appeared.
> >
> > Driving home (20 minutes), the radio was intermittent. The radio went
> > off altogether. The truck began "missing" or running poorly. I made
> > it home, parked, turned off the engine, tried to turn it over, and it
> > made the dreaded clicking sound.
> >
> > Any help appreciated!
> >
> > Mike
>
> Easy to test. Get a cheap voltmeter. (even the free HF units will work
> for this)
> Hook the meter up to the battery posts with it set to DC voltage and
> read the voltage.
> Jump start or charge the battery till the truck will start.
>
> With the engine running you should see a voltage at the battery posts
> rise to close to 14-15 volts if the alternator is working. If the
> voltage doesn't rise the alternator MAY be bad.
>
> Check fuse number 11 (20 amp) in the junction box under the hood. If it
> blows or corrodes the alternator will stop working.
>
> Also check the battery cables, the connections on the starter relay and
> the connections on the alternator. Wiggle them around while watching the
> meter. If the wires corrode internally they could cause this as well.
>
>
> --
> Steve W.

Hi Steve,

Thanks for your help! I jumped the truck and checked the voltage. It started out at 14 and then slowly leaked down to nothing. I then switched the 11 fuse with another 20 amp fuse and tried again, but I got the same result. Wiggled the wires to no effect. It sounds like the alternator.

Mike