When I punch off the Airconditioning button the light goes out, but the a/c keeps running cold until I shut off the engine. On engine restart the a/c is then off. The a/c can be switched on again after start-up. I have no climate control package, only the simple system.

What needs fixing under the hood of my 2000 GMC Sierra 6L?

There is an electrical connection at the a/c compressor which controls the activation of the a/c clutch. You need to find out if you are getting power at this connection after you shut off the a/c.

If you have power at the connection, then the problem is most likely with the a/c controller.

If there is no power and the a/c is still on, then the clutch is sticking and needs to be replaced.

//2000CAYukon

There is an electrical connection at the a/c compressor which controls the activation of the a/c clutch. You need to find out if you are getting power at this connection after you shut off the a/c.

If you have power at the connection, then the problem is most likely with the a/c controller.

If there is no power and the a/c is still on, then the clutch is sticking and needs to be replaced.

//2000CAYukon

Thanks...........I'll get the meter on the compressor end early next week when I have time. Here's hoping the A/C keeps running for this weekend - I'll need it!