AC system problem

[greatjorb88]

Hey there. I was wondering if I could get some help on this. It seems that every time I turn on the defog/heat in my car, the ac compressor starts to make a NASTY harsh noise. Almost like a really unhealthy snarl. And it gets worse with how high you rev the engine. The heater works fine as long as you keep it on "heat" but as soon as you turn it to "defog/heat", within seconds you can hear the noise. The part that worries me is I can feel it through the gas pedal. That really makes me nervous so I try not to run it, but it's kind of important to have especially in winter. The AC system has other problems as well, such as the fan is either off, or on full blast. Also, the "defog/heat" button works, but just plain "defog" doesn't. I'm running a '90 legacy L NA. Is my compressor bad? Any input is great, thanks

[beatersubi]

It sounds like the clutch on the compressor is going. But it could be as simple as a loose belt. Its hard to diagnose w/o hearing it in person. Can you see the clutch engaging when the defrost is on, and does the pulley continue to rotate?

You could unplug the compressor as a temporary fix, until you're ready to fix/replace it. I've been running w/o A/C for a while and the defrost works fine on my car.

[greatjorb88]

I'm not sure. I'll have to take a closer look. All I did before was lift up the hood when it was making that moise and I could definately tell it was coming from the compressor. It hasn't been doing it since after I posted this though, so who knows what's goin on. That sounds like a good solution to unplug it though. If it starts acting up again I might just do that. Thanks!