That's going to depend on what engine you have. If you have the Cummins ISX, it'll be on the left side of the vehicle, towards the front of the engine, and the high pressure fuel pump will sit above it.
First you should find out the dimensions of your pick up truck, and then find the dimensions of an individual portable air compressor. Then, with some simple math (truck dimensions divided by the measurements of one air compressor), you'll know how many air compressors you can fit into the pickup truck.
Bad compressor? Air leak in system? Excessive vehicle weight?
You can find a diagram for replacing the air conditioning compressor on your 1994 Chevy 1500 pickup truck in a Chevy service manual. Many auto-parts stores will supply the diagram when you purchase the air conditioning compressor.
Any air compressor that can achieve and hold 100psi will run an air gun. the larger the tank the more lugs you can remove before the compressor will need to run again.
If it is working fine, and the noise is only when it is disengaged you should only need to change the clutch on the compressor not the entire compressor. If there is room to pull the clutch off on the truck, then there is no need to evacuate the refrigerant.
You remove the compressor and replace the belt with one for a truck with out ac
That refrigerant oil
you need to drain all the freeon out of the system. take the belts off. and take the bolts on the compressor out. its best to get under the truck. and there is a lot of wiggling to get out.
As long as the compressor is the correct one for the unit and the compressor was not damaged in the error (as it can if fed liquid refrigerant). No fault will be evident as the compressor can only pump one direction.
Your 1989 Chevy truck air-conditioner condensation drain can be found on the bottom of the air conditioner compressor. The air conditioner condensation drain routes condensation to the bottom of the engine compartment.
You need a bracket made to fit your compressor and truck. There should be unused tapped holes in the block. You may also use some longer bolts at the water pump. See ACKITS.com
Disconnect the air lines to it, unbolt it, installation is opposite of reverse. You should be able to look at it and figure it out.