Auto Air Conditioning & Heater Repair: A/C compressor questions for Chevy Express Conversion van, chevy express, head gaskets

Question
Hi, I have a 1997 Chevy Express Conversion van and I need to replace the compressor (and accumulator and orifice tube). The old compressor has an electrical connection in the back as well as on top but the NEW compressor does not have the rear connection? I'm guessing this is an additional high pressure switch. Would it be appropriate to short this with a wire and tape it up or do I need to bring this compressor back for another?

Also, their are two stickers in the engine compartment: one says rear air, 4lbs 8 ozs of refrigerant, the other says "use an additional 7 ounces of refrigerant and extra pag oil" How much "Extra pag oil" does this mean?

And my final question is: do you know where I might find the orifice tube in this van?

Thanks for your help. I've done a lot of auto repair over the past 25 years including head gaskets and just about everything BUT A/C so your help is really appreciated!

Answer
Hi Jim

This high pressure switch is a protection for you compressor.  If you remove it you will shorten the life of the comp.  Just remove the clip at the switch and install switch to new comp.  The orifice tube is located at the evaporator inlet (the thinner of the two pipes).  Your charge should ben 4lbs 8 oz.