Acceleration Issues....
 

It figures...

So, I have a 2003 V.6 Mustang that I let my mother use for a while because her SuV has had it. Thanks to her, it's now pushing 78,000 miles. Anyways, I noticed a very loud serpentine squeal a couple months ago. I'm almost certain that the cause is the diodes in the alternator are giving out. And because I don't drive too terribly many miles in a given week, I decided to milk the rest of the use out of the alternator before I break down for another one.

Well, a couple of months later, the squeal has greatly diminished in pitch, volume, and consistency; but it is still very present. The reason that I'm asking is, now the damn thing has developed some sort of acceleration problem. It is extremely sluggish and doesn't want to accelerate. I don't think this is related to the diodes in the alternator, but am by no means a mechanic. Has anyone a similar experience or any ideas as to what might be causing very noticeable acceleration issues? I had a gut feeling that it wouldn't be long before the whole thing started falling apart in rapid succession the second I let her get her hands on it, but whatever. That's life... :/

lol diodes in the alternator will have nothing to do with either problem as far as i'm aware of. the diodes in my alternator have been bad for like 2-3 years and i'm still using it.

if your belt is squeeling, it could be several things. most commonly, your belt just needs replacing. it could me more indepth such as the tensioner wearing out or your AC or some other accessory freezing up.

as far as the acceleration, that could be ANY number of things. does it feel like your misfiring? do you have any check engine light codes OTHER than the alternator?