On my way home tonight I heard a high pitch squeel from under the hood and my battery guage went to zero. Is this most likely an alternator problem and if so, how difficult is it to change?

 

It could possibly be the alt, but it could also be another pulley causing the belt to stop moving for a sec.

Chances are its indeed the alt pulley, but you should poke around to check.

Loosen the belt and check all pulleys. The tensioner will be two or three bolts on your psteering pump assy.

 

This happens to both my jeeps every winter, happened this morning going to work but its when my belt gets wet and cold and slips. I just stomp on it and it grabs again, tighten that belt up more. But if it is a pulley thats being a pain in the ***, take the belt off and spin each one by hand until you find the one that is hard to spin/feels like its grinding/has forward backward play in it.

 

They should be able to spin on their own. Grab one and spin it hard (think Price Is Right wheel spin) if it continues to spin for a little bit after doing so they should be good...if it immediately stops or makes any noises and/or back and forth movement it may be time to replace.

 

Only if the belt is off.