Just like the title says.. bought the truck with no ac so I bought everything to put it back in and my compressor isn't kicking on what are some things I can look for does the control switch inside the truck control that

 

Does it have enough refrigerant?

 

I was in the process of filing it but had to stop everything is brand new so the system was empty how much freon should be in it before it kick in? Thanks GLC for replying

 

Are we supposed to just guess at what you're working on?

 

I shouldn't have to do this, but I looked in your other threads and see that you have a 99 with a 5.4 - PLEASE make a sig or fill in your profile so we don't have to guess what you have.

F SERIES FULLSIZE PICKUP
1998-2004 All Engines - Lightduty ... R134a 33.00 PAG 46 9.00

That's 33 ounces of R134a refrigerant and 9 ounces of PAG 46 compressor oil. You must put a full vacuum on the system to completely evacuate it after completely flushing it before introducing the measured amount of refrigerant and oil.

 

I'm sorry guys I thought I had all that stuff on there before but I must be mistaken... I'll look into fixing all that.. so in order for the compressor to kick on it must have that much oil and refrigerant has to be e in there in it? Thanks guys for your input

 

It has to have something pretty close to that - there is a low pressure switch.

 

No, it doesn't. The oil does have to be in there first with the correct amount in each component, but you do not have the capability of injecting the refrigerant into a non-running system like the factory does without investing thousands of dollars for the right machine.

When charging from a can or cylinder, it is the pressure from that container that "makes" the low pressure cycling switch and allows the refrigerant to be pulled in by the vacuum effect of the compressor pump. If you've properly evacuated the system first and it's under a deep vacuum when you start charging, you'll find that a pretty good amount of the refrigerant will just "jump" right into the system due to the vacuum. Once the pressures equalize, then you can start the engine, turn on the system, and, assuming there are no system faults that inhibit compressor operation, finish charging the system by using the compressor to pull in the remainder of the charge.

If the compressor doesn't when there is a minum of 45 psi in the system, you have a fault that's keeping the system from operating and you must repair that fault in order to continue.

 

Did you put the correct amount of oil in the compressor before installing?

I use a pot of hot water to set the refrigerant can in when I'm charging so the refrigerant will evaporate quicker. It takes a long time otherwise to charge the system waiting on the ambient air to provide the heat of vaporization for the refrigerant.