A/C compressor won't turn off

[dydx]

Hey guys, just picked up a 98 GS today and I love it! Of course it's not new (110k mi) so it's got some issues, but the most concerning of which is the air conditioning... It is THE COLDEST air conditioning I think I've ever felt and it won't turn off. The A/C button in the HVAC controls doesn't light up when I press it down. In fact, pressing it doesn't make any difference. The air still blows freezing cold. Even when I turn the fan speed control knob to "off," I can't hear the compressor cut off. Also, when it's off and in non-recirc mode, the air coming through the vents is still cold.

Any of yall have a similar problem before? I honestly know nothing about how the A/C system works, but if I had to take a shot I'd guess it's the control panel due to the light not turning on/off? Or maybe the ECU?

 

[mondale]

Do you have the "automatic air" ? Either way it sounds like the ac compressor could be shorted to power. Unplug the AC compressor clutch relay. Does the compressor clutch still engauge? There are a few options for power to get to the compressor coil which will cause it to draw the compressor clutch towards it, causing the compressor to pump refrigerant. Can you read wiring diagrams well? Look in your service manual and trace the wires (black/white) from the compressor clutch connector back to other connectors, and start eliminating parts of the circuit that may be at fault/shorting power.

 

[dydx]

Okay I'll check that out when I get back in town. Also, there's a LOT of condensation under the dash in the passenger side footwell. I'm assuming that's not directly related to the problem, but maybe slightly so.

Edit: it uses manual HVAC controls