AC on makes volts drop and belt squeeeeeeeellllll

[91coMANche]

So now that I have my AC blowing ICY cold another small issue has shown its head. When I have the AC on high the volts will drop to 12 at idle...when I give it gas the belt squeels and slips but the volts rise to 14.4. Is my alternator dying? Belt is tight and a new gatorback.

[HOrnbrod]

My 91 has done that from day one. With the A/C on, electric fans running, the VM drops to about 10-11 volts at idle. I even have larger mains cables and a 134A ZJ alternator. But at the battery it's always about 14.5V. I spoke to Jon Kelly over at NAXJA (he markets the larger mains cables) and he said it's common with the 91's he's worked on because of where the factory hooked up the positive sensing lead. As long as you read the correct voltage across the battery I wouldn't be concerned.

 

Squealing belt? Might be glazed and need replacement or it's too loose.

[jeepsouth]

I just got my a/c going again also ,and i too have lower voltage while running. I have replaced my clutch fan with an electric one though so more power used there.The aux. fan runs with the a/c compressor this takes some power to run. May be just that.

[91coMANche]

Good so I have no problem!

[Rymanrph]

When my belt squeeled with the AC, it was because the belt was too loose.

[Akula69]

Actually have the same problem when the A/C is on (except the belt does not squeal). I even replaced the alternator with a 100 amp model and it made no difference....but I do get the correct vots across the terminals, the lights do not dim and it has not failed to start when needed.