Need help connecting my a/c compressor.

[low91]

Does anyone know the size of the hoses and fittings needed to connect a LS truck compressor to the rest of the system on an OBS truck? I planned on using the peanut style compressor blocks from here,Sending Unit Wizard, and just get the hoses made but I need to know the sizes for the fittings at the evaporator and condensor and also what fittings would have to be built into the hose for charging the system.

Sorry for all the questions, I'm not really familiar with a/c's since i haven't had one in the ten years i've been driving lol.Thanks

[LS1GMCTruck]

Are you able to simply drive it over to a A/C hose shop & have them make them up? They are generally quite affordable to have them make them, even at a drive up shop. Less than $40.00 & your good to go. But...If your in a rural area, that might be a problem.

[low91]

I thought about that but theres not really any shops around here that specialize in a/c services.

[low91]

I think I may have the hoses figured out but does anyone know how to wire the system? Should I use the wiring from the old harness and just wire on the pigtail for the new compressor? or does the LS compressor have to be operated by the new PCM? and if so how do I incorperate my original controls?

[LS1GMCTruck]

I think I may have the hoses figured out but does anyone know how to wire the system? Should I use the wiring from the old harness and just wire on the pigtail for the new compressor? or does the LS compressor have to be operated by the new PCM? and if so how do I incorperate my original controls?

NITROUS! Where are you? He knows this A/C stuff, on our trucks. Let me try to remember. You have a A/C request wire that comes from your dash control. This gets wired to one side of your two-wire low pressure switch thats on your accumulator on the firewall. The other wire from the accumulator switch connects to your A/C request wire coming from your computer. Also from the computer, is a wire that activates the relay, that cycles the compressor on & off. You should also have an A/C sensor plug/wire coming off the harness, that plugs into a hi-pressure side sensor that should be intalled on the hi-pressure side hose somewhere. RedHeartBeat knows this **** too.

[low91]

Lol yeah I had hoped Nitrous would chime in. I remember he kept the LS A/C comp.

[low91]

I got my compressor fittings in and it looks like theres no way I'll be able to use the compressor in the factory location the lines come out right into the forward a-arm mount. Does anyone know of a bracket that would move the stock compressor up top? If not, would I wire a Sanden compressor the same way stated above?

[NITROUS]

low91, post a pic of your setup so we can see which way you need to go. There's plenty of options, I just need to see your current configuration but the F-body compressor fittings will eat you alive since they come out of the back of the comopressor. I have a small hitachi compressor that would probably work great but I need to get the numbers from work Monday. I used the 2002 F-body HP switch and it's installed behind the grill on the condenser. If I remember correctly pin 17 on th pcm goies to the relay and pin 18 goes to the clutch. The green wire from the relay will go to the LP switch. The HP switch grey wire goes to pin 45 which should be the 5 volt reference for refrigerant pressure. I believe the high pressure switch actually has 3 wires which are black (ground) grey (5 volt reference) and red/black (refrigerant pressure signal). This is the switch to the PCM that's tied to your DTC's. The Low pressure switch could actually just go to the clutch to kick it on and off based on pressure demand.

[NITROUS]

BTW, I just pulled this out of memory so I might need to look at my notes if I gave you the wrong pin numbers.

[low91]

If I could just find the smaller fitting in a forward 90* I think I could maybe make it work, it would be a tight fit. I really want to try to keep the comp. where its at, I hate the idea of that huge notch being empty