I just replaced my compressor on my 94 pickup 2wd 22RE 4cyl. I took it to get charged and the clutch won't engage, so it won't charge with freon. Is there a relay or fuse that could have gone bad? Is there a low pressure switch that needs to be bypassed. The guy I took it to is not to familiar with the older toyota trucks. I really can't afford to take it to a machanic to trouble shoot this. I just want to get it fixed so I can take it back and get it charged.
Its going to be 115 degrees today and 117 tomorrow so Having my a/c fixed would be great.
Thanks for your help in advance.

 

There is a fuse I believe on the left side right above the kick panel , shoukd be a heater relay beside it . If the compressor and clutch went bad chances are it blew the fuse.