[A_G_RIDE]

I've got a 98 GT and I've recently started having a couple of problems with my car first of all it makes a loud squeaking noise, and my dash signals that my battery is low (dont know if one compliments the other) When I turn it on in the morning it's starts squeaking loudly, after running it for a few miles the squeaking goes away but when I turn on the A/C the squeaking returns and louder than it was before. I've also noticed that my battery gauge in my instrument panel goes down past the normal center line. When my car is idle the battery gauge marker is dead center, when i turn on the lights it moves slighty to the negative, when i add the A/C it drops much much lower than that, towards the N on the NORMAL battery marking. Went to Kragen and they told me it was fine. I've purchased a Tensioner, Tensioner Pulley, Alternator, and fan belt but to no avail does the squeaking go away. If you guys have any suggestions they are greatly appreciated.

 

[bgt98]

HAve you set the proper tension on the belt? Sometimes if its not tight enough or too tight it will squeak. Check all pulleys that the belt touches to make sure that they're all solid and a bearing isn't worn out.
The "battery gauge" in your dash board is actually showing the existing charging ability of your alternator. It will fluctuate given that your alternator puts out different amperages at different engine speeds. The alternator still shows its charging fine. My first guess would be that the voltage regulator is starting to lose its spunk.
Do you have any big stereo equipment, air ride suspension or anything of the like that you are running in your mustang?

 

[GR40Snake]

I suggest one of those stethoscopes for listening to engines to pinpoint where the sound is coming from. Found at any auto parts stores. The sound might also be coming from the Secondary Air Injection Pump located in the front passenger side in front of the wheel?