AC problem clutch not engaging

I have a 1999 Chevy Blazer with the 4.3 and manual climate control. I just replaced my compressor, drier, and orifice tube. I started adding Freon back to the system but the compressor will not engage, I did the jumper wire on the switch at the drier and the motor revs but the clutch doesn't engage. I only have about 3/4 a can in it now. My low side is 90 and hi is 85 with a/c on max and blower on high. Any ideas? Thanks,

Check all fuses and jumper compresser clutch to make sure it works.
Did you get the high side switch on back of compresser and have it pluged in?
Was it working before you replace compresser?

MT

Check all fuses and jumper compresser clutch to make sure it works.

I found a blown fuse in the fuse box under the hood, it's the 10 amp one that shows ac on it in the manual. I replaced it and turned the ac on and it blew again.

Did you get the high side switch on back of compresser and have it pluged in?


Yes it is plug in. My new compressor didn't have one so I used the old one. Could I have installed it wrong?

Was it working before you replace compresser?

Yes, as long as it had freon. It was leaking around the back of the compessor housing, a charge would only last a few days.

That fuse feeds the ac compresser clutch relay.
If it is blowing you have a short in the wiring or relay or ac compresser clutch circuit.

Thake a fused 10 amp jumper and jump the ac clutch.

If it blows check the clutch coil and wiring for shorts.
There is a jumper diode in the clutch plugin that also could be shorted to ground.

Check it for one way current.
Good Luck and
Let us know what you find.
MT

How do you mean jumper the clutch? Run a pos. & neg. form the battery to the plug by the clutch? I still have my old compressor. If I connect it back up without installing it will it click or something, just so I can make sure it's not my wiring? Could my rebuilt compressor be bad?

I replaced the fuse again and unplugged the connector on the front of the compressor then checked for voltage, it has 14v on it. So you think the compressor is bad? If I plug it back in it will blow again. Thanks,

Just checked the connector on the compressor with my meter and it has 5 ohms.

Unless the diode in plug is shorting out.
You have a shorted clutch coil.
To jumper the clutch coil hook a 12 volt fused jumper wire to the positive wire going to clutch coil.
MT

After replacing the compressor with another one and vacuuming the system I now have 29 Lo and 181 Hi with 44F at the vents. Does this look ok? Thanks Mt for the help so far.

You are welcome and thanks for posting back how it went.

Pressure looks good.
If you added the correct R-134a charge you are in good shape.
28-32 is good low side.
200-250 high side is good.
With engine tempt and ambient temp the and more rpm high side will raise some
I always like to check pressures at idle and at 2K rpm with compressor running.
Good luck
MT