89GreyStang

As I accelerate the a/c fan slows down. At idle or when I am decelerating the Fan blows at normal speed. When tested using a Voltmeter, at idle, the Alt shows 14.27v. While driving the guage (in the dash) show a little under 13v. This just started about a week ago. Go figure just when the temps are reaching 100.

Could the high speed circuit in the alternator be bad ? or is it something else ? The radio and everything else seems to work OK. I know it is odd. I put the 3G (130 Amp) in about 2 years ago because the 2G (75 AMP) Alt was just not keping all the device going, and the battery charged. But this time it seems to be odd that just the A/C fan is winding down and only while accelerating.

Any ideas ?

Thanks in Advance...

Glen..

mustang8719

Are you sure the fan itself is slowing down or is it just the air flow?
You might have a bad diaphram and when you accelerate then you lose vaccum to the system and it changes to defrost or just drops off.

settled4automatic

is it upon any acceleration or at WOT? i believe there's a switch to override your a/c at WOT.

89GreyStang

It is not at WOT. It happens as the RPM builds like entering the ramp to an x-way.

The diaphram sounds plausible. My initial thoughts were vacuum but in checking all the lines they seemed fine. I'll check out the diaphram tonight.

I thought it was the Alt but today I watched the power output on the Alt as I acceleratted. No dip in output.