Ok Im working on building from scratch a AC system in my v8 TJ. Im using GM Denso 10S17F 10S20F that came with the 4.8 .

I used these adapters to mate the compressor to the TJ , using the TJ condenser, dryer, and expansion valve.http://www.nostalgicairparts.com/air...10s20f-593.php
And I had the lines built by my local NAPA store.

It will have a low press switch on the dryer and a high pressure switch in the high pressure line.

The questions I have are,

Is the function of the high pressure switch strictly for system protection in case of over pressure or is its function to cycle the compressor clutch off and on?

Im told this compressor is basically a variable load internally to reduce drag and improve MPG by decreasing load when demand is low. IDK

Im planing on building a relay circuit to engage the clutch via a switch and the two safety switches will just break the ground to this relay if too low or too high.

Another assumption is this compressor going to work with expansion valve being the truck it was in had a orifice tube. IDK real difference and was hoping that a pump is just a pump.

Ideas ,, Opinions?
Lowell

 

high pressure switch in any a/c system is a shut off for the compressor to protect the entire system.

with your relay circuit what kind of switch are you talking about? if you are talking about a toggle that would be a bad idea with just pressure switches for safety. vehicle systems are not designed to run 100%.

 

I was just going to use a 30 amp relay tripped by toggle switch. The relay would engage the clutch. The two pressure switches would complete the ground for this relay.

The parts catalog says the high pressure switch is actually called a cycle switch. That seems to support idea that the function of that switch is to turn off the clutch . Agree?



Ideas?

 

The function of the switch is to turn off the clutch, strictly for system protection in case of over pressure.

 

You want the High Pressure switch to trip as few times as possibly. Balance the load with some sort of temperature sensor so you can either run the compressor continuously without tripping the high pressure or allow it to be cycled off by reaching a set temp.

 

Ok I think I get it ,

so if I install a temp sensor in the cab and loop it to the ground of the relay also it , and (or) the sensors will cut out the clutch. Correct?

I guessing the original setup used the BCM to control the ac ?

Thanks

 

I found this thermostat , it looks like all I would have to do is install it in the evaporator box and tie it to the relay ground.

Preset Thermostat With 12 Inch Capillary Tube - AC Thermostat

 

Why not just use the GM pcm to control the AC?

 

thanks I will research that , but I dont have the BCM and Im thinking I would need it also.

I finished building the relay cir and tied into the High and Low switches, Its charged and I will do a test asap