I have a squeek that starts small then gets worse as the engine heats up. I have changed the alternator and both of the belt pulleys and the squeek is still present, like a bearing going bad. The sound increases as the rpm increases. Any ideas on what the problem is would be appreciated. It is on a 96 F150 5.0 with 196,000 miles.

 

It's probably the WP pulley. There's a TSB about it. Go to FSB's Tech Writeups forum & find the "TSB & FSA" thread, and scroll down to that one. It includes the updated PNs.