Recently I replaced the valve cover gasket on my 2004 Dakota. I had to loosen the A/C compressor and move it out of the way to get the Valve cover off. Now the A/C isn't working, the pulley turns but when you turn A/C on the clutch does not engage.

 

Is the clutch plugged in? Pinch the wiring somewhere?

 

If coolant was low would that cause clutch to not work?

 

If refrigerant was low, yeah, compressor won't run. Engine coolant though? Nope. Doesn't care.

If it worked before you did the gasket, didn't open the system, then it should still work. Probably just something not plugged in yet.

 

Check the connector and wires that come from the A/C pulley. Does it try to engage the clutch? Or is it just not doing anything? To engage the clutch it needs to see a low enough pressure on the high side. Check your pressure switches and make sure you didn't unplug or damage one of them. Ones on the dryer and one is on the hardline above the compressor itself.