This has been a complete nightmare from the start. Here'* the low down though:

I bought a new compressor, Accumulator, Orifice tube and low pressure cut-off switch.

I eventually got everything installed, all hoses and electrical fittings connected.

Put the belt on, started up the car, turned AC to max and high fan setting. The compressor clutch didn't engage...wasn't making any sounds or anything. I figured there was no refrigerant in it, so as per the directions on the can, I put in one can of R-134a. The can has a pressure gauge too, but even after i put that can in, the gauge didn't move from zero. And the compressor still never kicked on.

I check the only fuse i know of (above the brake pedal) and it was fine. I triple check all of my connections, and everything is connected correctly.

What could be the problem? Does the system need to be vacuum pumped before I can recharge it with R-134a? Did I miss a step somewhere in the process that is keeping this clutch from coming on? Please help me fix this AC once and for all!

Ok, first, the system should have a vacuum applied to it before recharging to get all the moisture out. It will still work if you don't, but will work better if you do. I've been pulling 30in of vac on the systems for half an hour and getting good results.

Next, unplug harness connector at the low pressure switch (the one on the accumulator) and jumper the two wires together for a moment, that should blip the clutch on to prove you have power to the compressor clutch. If that doesn't kick on the compressor, then start checking the wiring again all the way back to the relay that runs the clutch. You may find a second fuse block near it (ran across that with an '97 Astro van yesterday..two A/C fuses, one under the dash and one in the engine bay for the actual clutch circuit.) You can also jumper across the relay socket to force the clutch on in case your relay is bad or contacts are dirty.

Usually, the system will begin to cycle after about 6 to 8 oz of refridgerant is in the system. The compressor will run continuously when you are getting close to a full charge in it. I don't trust can gauges, borrow/buy a set of manifold gauges from the autoparts store so you can see both the high and low pressure circuits at the same time.

ok, should i jumper the two together while the engine is running?

Also, that connector is not keyed, does it matter which way i plug it onto the accumulator?

BTW, i will take it to get a vacuum put on it. Thanks.

What is the proper name for this...Evacuating?

Yep to the first (you neet power for the clutch and it will not hurt the compressor to spin it up)

No to the second, the plug may be keyed (newer WeatherPak) or not (older blade connectors) It doesn't matter which way it plugs in on the older style, since the switch is just a SPST contact.

ok...im going out now to give it a try....I also just read a post in the electrical forum...the guy said his compressor wasn't getting power, someone recommended to switch the AC and horn relay (as long as the horn is working) to test the relay portion of the system. So i'll give them a try and respond back in about 5-10 minutes....Thank you

-Steve

Ok, i jumpered the two slots of the connector that plugs into the accumulator. The engine was running and the AC was turned on. When i jumped the two together, a load was put on the engine (due to the change in rpms) and the load was taken off when i disconnected one of the wires. But the clutch never engaged.

I need to find which relay is for the horn and which is for the AC now...is that labeled anywhere, or would it be in my haynes manual?

Ok, i switched the two relays and nothing changed. The horn still worked, the AC didn't, and i tried to jumper the connector terminals again and got the same outcome as before...a load put on and off the engine. What now?

Ok, you put power directly to the clutch coil and it didn't engage. Sounds like the new compressor clutch is bad. Welcome to the world of Garbage replacement parts.

To be absolutely sure it'* a bad clutch, run battery power directly to the clutch (doesn't matter which posts you connect the positive and ground wires to, the clutch is just a coil of wire like a big solenoid.

Just to be perfectly clear here...I should take off the compressor, and apply 12 volts DC from the battery to the two terminals just above the clutch (where the connector attaches to the compressor). If the clutch turns, then there is a problem somewhere else, if it doesn't turn, then the compressor is bad. Correct?