A/C problem

[whitepony91]

I recently had a new motor put in my car. my air conditioner worked befor. the night i brought the car home after the new motor was put in, it didnt work. I asked him if he forgot to recharge the system, he said that he didnt have to discharge it, he just lifted the whole unit up and out, hows that sound?. I asked him if he could look at it and see what was up with it, he said it would cost me more money to get it fixed. Obviously it is omething that he did. I checked the pump on it, when i turn the ac on high, the clutch doesnt even enguage on it, ya know, the lil "click" that ya hear. I was wondering if there might be something simple that i am overlooking, or any possible solutions you could see. i dont see any unconnected wires, but of course i might be looking in the wrong place.

Thanks a lot

Oh, also when i am taking off from a dead stop, or going into reverse, i sometimes hear a grinding sound comming from the back of the car. er maybe not a grinding sound, more like the sound that a wood floor makes when ya step on it and it creeks. does this mean that my rear end gear is goin bad?