Air conditioning help please
Any help or suggestions will be much appreciated!
Pictures of my two trinary sw and one of the binary sw on the POA valve.


on a second look that's your low side.. you want the pressure sensor on the high side line.. that's your low pressure cut off switch. you should be able to leave it alone or cap it off
http://www.nostalgicairparts.com/air...h-port-376.php
Or does someone make a fitting to take the factory switch that I have?
BTW, what is the difference between the two trinary switches I have pictured above?
Thanks!
the sensor with the male fitting you have looks like a oil pressure switch.
Im not going to bullshit you im no expert on these conversions. but with my background I know enough to be dangerous

also look up the wiring for the ls2 and the a/c if I recall correctly the ls2 pcms at least the GTO uses the BCM to run the A/C if thats the case you have more in store for your a/c wiring. the ls1 systems are PCM controlled and are very simple to wire up and have working
Last edited by 89 formula350; Feb 1, 2011 at 11:16 PM.
the sensor with the male fitting you have looks like a oil pressure switch.
Im not going to bullshit you im no expert on these conversions. but with my background I know enough to be dangerous

also look up the wiring for the ls2 and the a/c if I recall correctly the ls2 pcms at least the GTO uses the BCM to run the A/C if thats the case you have more in store for your a/c wiring. the ls1 systems are PCM controlled and are very simple to wire up and have working
One thing I didn't mention is that I am using a stand alone harness from Speartech. The harness has a green wire 12v call for ac, the trinary sw for pressure confirmation/fan operation, two wires for the fan control primary and ac.
So from the way I understand it all I need to do is find something that will get my trinary sw in the high side of the ac for the ecm to control the compressor. The poa valve will control the amount of pressure back to the compressor. Am I wrong in my thinking?
Here's a description of the poa valve:
Like the suction valve, the POA valve is a suction throttling device that is located at the outlet of the A/C evaporator and is used to control the amount of compressor suction on the evaporator.
The POA valve was used on some General Motors and Ford air conditioning systems through the 1970�s. On these A/C systems, the compressor would run constantly whenever the A/C system was on. Under certain operating conditions, less compressor suction was required on the evaporator. The POA valve would then close off the flow of refrigerant, effectively reducing the amount of compressor suction.
BTW; You were right! That is the oil pressure sending unit... Its been a while since I've been working on this project, I really need to get it DONE!
you might be best off simplifying this setup. remove the valve and allow the compressor to work as its designed with the switch on the high side like you said.
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you might be best off simplifying this setup. remove the valve and allow the compressor to work as its designed with the switch on the high side like you said.
1989 Formula350,
Does this look like a fitting I could braze into a line on the high side for my trinary sw? -> http://www.tubesnhoses.com/proddetail.asp?prod=4166
I did some looking into what you are saying about the ls compressor and the wave plates, I couldn't find much info on how they work. I am going to start looking for a mobile ac guy to come out and look at what I am doing.
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