SharkSkin

Definitely start by jumpering that switch. If that works, forget about going into the console... but I'd recommend altering the wiring by inserting a relay, activated by the existing circuit and feeding the fused 12V for the compressor from somewhere else. Ideally, the wimpy switch in the console should only trigger a relay. It's not really up to the job of handling the large inductive load of the AC clutch. Save yourself the PITA of upgrading the relay in the console...

928FIXER

Check the connections at the defrost switch...I've seen them get very loose and all the compressor power runs through it.Why did the clutch burn up?Has this problem been rectified??If not you will burn up this clutch too.

docmirror

Yeah, I've got the same prob on my car. The fluid was filled, the connections were connected, all systems go! Driving down the road, nice and cool, what do I smell? That sickly sweet plastic melting? Yep! The relay in the console is melting, and the smell is wafting on a vacuum up into the center vent outlet. And now, blowing warm, need new relay. You can buy any kind of relay rated for 5 amps or more. Make sure the coil side is 14VDC. Do not use an AC type relay, or the coil may burn. Coil resistance should be >200 ohms. The Nichols write-up Tip055 and diagram is just the fix for this.

Doc 90GT in resto