My 300td which I've had for about 3 weeks now has the a/c compressor missing. I'm guessing that it's been gone for more than a year or two.

I need to replace the heater matrix which leaked and have a non-ac unit as a spare, However, I'm not sure whether to try & resurect the a/c system. I think the heater matrixes are different so I have to decide now which way to go - a/c or non-a/c.

Am I likely to me wasting my time & money trying to get the a/c system up & working again? Will exposure to atmosphere cause harm to the A/C system internals?
Steve