Getting hard to start, gauges occasionally shutter on startup, and today the radio wouldn't work for the first 5 mins of drive time.

I would assume it is but the battery gauge reads strong so thats what is confusing me.

btw, its been like 5 degrees here, so that could factor in.

so, is it the battery, or is it the alternator, or is it something else?

any thoughts?

 

Make sure your battery terminals are secure and clean first of all. Sounds more like an alternator to me, but hard to say. In my experience I have found that when an alternator or battery goes, the other is not far behind. Also, I believe my battery started reading slightly HIGHER right before my alternator went on me a few years back.(not an f150) A shop would be able to run a quick test for you for free/cheap.

 

I would get the battery checked ASAP. Gauges will stutter when the battery is low! If the battery is low, then the alternator will be working overtime. From what your describing.. i would have to assume that your battery is on it's way out. Also, If you have any aftermarket things attached to your battery, you can also loose the solid connection needed. Make sure terminals are clean also. But definitely check your battery first, explore other options only if the battery is showing a good charge.

Note: the fact that your battery gauge is reading strong i would have to assume shows that your alternator is working correctly, but probably very very hard. Turn your key on without starting the truck up and see what the gauge is reading first, just curious!

 

I believe that gauge on the dash measures voltage not amperage so it can be very deceiving. Amperage is what they would check when testing the alternator.
Check you connections, for sure. If you find nothing, take your battery into a parts place and they will test it. They will test the alternator too.
Why your radio won't play, well your truck would not have started if the battery was so low that the radio would not have played.

 

Fully charge the battery and then go to autozone or somewhere and have the battery tested. Normal life for a battery is 5 years, so if your 04 has the original battery in it, get a new one regardless

 

This happened to me! DO NOT let this go. You will be stranded (fortunately I was stranded in a Wal-mart parking lot so I bought an new battery there and was okay).

You can test your alternator yourself.

If it was me, I'd just replace the battery now and be safe.

 

From my experience AZ etc can only tell you if the battery has a charge. Not how well or long it will keep one.

Mine is also an 04 and had the factory battery.