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codyace · 03-13-2012, 11:02 PM

Hey Dave:

Operation of the compressor is one thing (as that's ONLY through the AC relay)...and yes you are correct there is not any sort of DoublePressure protection on that side of the house.

HOWEVER, where the Double Pressure switch (the only thing on the dryer) comes into play is how it allows for the air conditioned air, to get pumped/blown into the cabin. While I don't have the SOHC stuff to know 100%, I know from the DOHC aspect of things that the Double Pressure switch acts as the failsafe obviously between the push control unit, and the fan selection switch (essentially if the DP switch is shit, it won't allow you to even cycle the fans on to blow AC, even if the compressor is on and working)

Edit: The above in relation to the KA system (where the ECU has the pin for the ground signal to the AC relay, and the pin for the AC system to turn on in regard to the H/A system)

Edit: I can assure you this though, that once you dive into the actual HVAC system, it's a complex array of circuits to make it actually 'blow cold air'.

03-13-2012, 11:02 PM	#3
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 36 Posts: 8,030 Trader Rating: (58)	Hey Dave: Operation of the compressor is one thing (as that's ONLY through the AC relay)...and yes you are correct there is not any sort of DoublePressure protection on that side of the house. HOWEVER, where the Double Pressure switch (the only thing on the dryer) comes into play is how it allows for the air conditioned air, to get pumped/blown into the cabin. While I don't have the SOHC stuff to know 100%, I know from the DOHC aspect of things that the Double Pressure switch acts as the failsafe obviously between the push control unit, and the fan selection switch (essentially if the DP switch is shit, it won't allow you to even cycle the fans on to blow AC, even if the compressor is on and working) Edit: The above in relation to the KA system (where the ECU has the pin for the ground signal to the AC relay, and the pin for the AC system to turn on in regard to the H/A system) Edit: I can assure you this though, that once you dive into the actual HVAC system, it's a complex array of circuits to make it actually 'blow cold air'. __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy