My friend has and 96 Mud-Stang GT. That triangle shaped thing on the front of the A/C Compressor turns on when he has the heat on. I thought it was only supposed to come on when the A/C is on to run the compressor. I am not sure though, but anyway he says it's on when the heat is on and that it causes all the lights to dim, he said they are all right as long as he is on the highway doing 50 or 60mph. and it is making a funny noise like there is a loose part inside bouncing around. If anyone can offer any assistance it would be greatly appreciated. Thanks

 

AIZ,

I'm not sure how the Dorfs are wired, but GM cars operate the A/C clutch in the A/C, MAZ A/C, DEFROST, and BI-LEVEL positions, regardless of where the temperature control is set. If the controls are set to BI-LEVEL, for example, and at full HOT, the A/C compressor can still operate. Maybe that will help.

 

Okay that does help some. Because now i know it can come on with the heat but the piece that spins when the A/C clutch is on was spinning really slowly, while the other part of the pulley was spinning fine. This makes me think it is seized up or the clutch is bad. But on the other hand the little round ring thing was loose and it flopped around a little (description: the triangle piece has three holes in it and there are three little posts coming through those little holes, the posts are loose though inside these holes which makes me think this is part of the problem also .
Dorfs(lol)

 

On my Ford truck, the AC compressor engages if I have the selector switch in bi-level (dash vents and footwell vents) or either of the defroster positions. The only two positions that don't engage the AC are the dash-only and footwell-only.

This is all covered in the novel "Owners Manual" originally authored by Henry Ford. Check your local library or glove box.

Might post your Mustang questions on www.corral.net for better results.