The A/C compressor on my 79 f-150 is shot. Can I update the system to a more efficient model? I have the 300 inch six, and auto trans. I believe the A/C was dealer installed if that makes a difference.

 

I am in the process of doing the same thing. From what I have read, the best update is to increase the condenser size. A condenser from a van is a good upgrade. Also, always replace the drier. I do have a couple questions, and maybe this post will answer them.
Is there a good website with a AC schematic?
How do you determine which way the refrigerant flows through the evaporator?

 

You guys should go to http://www.ackits.com/ and check out the Seltec compressors and the Parallel Flow Condensers. I put the most humongous Parallel Flow condenser on my truck that would fit. My 77 has dealer air and everybody knows how ineffecient they are, but it now blows ice thanks to that condenser. Plus they are cheaper and lighter than factory units. They claim the condensers are 30% more efficient than the factory tube and fin of equal size.

They claim that the compressors are more efficient than the factory units although I don't have any experience with them. You can email them with questions and they are pretty good at answering them. (Except in the hot summer months)

As far as the refridgerant flow goes, it flows from the compressor to the condenser to the evaporator and then back into the compressor. Of course it also goes through various devices on its way such as orfice tubes, or expansion valves, receivers/driers, or accumulators, etc.

Thier are several web sites that will give you diagrams and info on a/c systems. I suggest that you check them out. Also we do have an A/C forum on this website. I would suggest that you move your post there as there are a lot of knowledgeable A/C guys there.

 

you are right, that is a good website. I will send them an email, as soon as I figure out what it is I need. Thanks

I am working on how to "move the post" to the A/C forum.

 

Big Perm,

You didn't give enough info.

AC schematic of what ?

Engine area
cab area
Electrical
Vacuum hose routing
Ducting

???????

 

Sorry Million, you are right, I was a little vague.

I was looking for a schematic of the refrigerant flow, similar to the one on this link I found:
http://autoacrepairs.com/EVSFlow.html

However, this link is probably generic, and is missing components or does not quite match what ford actually used on the our trucks. For example, where would the Service ports go? and should there be an overpressure saftey switch?

I am under the assumption that the dealer A/C uses a thermistatic expansion valve instead of an orifice tube.

Thanks you for any information!

 

The refrigerant flow website that you list should be almost identical to your system if you have dealer air. The dealer air does use the expansion valve and receiver/drier. Unless your system was modified for 134 it won't have a high pressure switch.

The service ports should be right on the compressor head. The low side service port (or suction) is on the suction side of the compressor. This port is marked with a big S near the port. The high side service port is on the high pressure outlet. The high pressure side is the one that goes directly to the condenser. If you have the York type compressor the ports are on the head.

You never know what you are going to get with dealer air, but all of the dealer air units that I have seen are like this.

I hope this helps, Gary

 

Ive seen some pretty good info in the A/C forum on here. But since the search feature isnt up and running yet it might be hard to find. Or just ask around in there. Theres some pretty sharp guys in there.