How much refrigerant is needed to kick the ac clutch on for an empty system?

[hoffa65]

you should have a lightr geen wire coming from the heater control harness along with 2 vacuum lines and some wiring for the fan. That should have 12vdc on it when AC i selected on the controls. That wire needs to go to low pressure switch, then off the other side of the switch (usually 2 wires dark green) to ac compressor and high idle sol (I use one to signal electric fan relay). AC compressor should ground and head or intake on a black wire. sounds like its still got some ECM connections left over

 

[hoffa65]

wire it like this

 

[TURNA]

Some models the is AC linked into the ECM and you have to ground a wire

Hold on Ill go look under the hood and tell you which to ground

 

[TURNA]

 

[565bbchevy]

So this is the brown wire coming out of this relay.

 

[hoffa65]

IMO if your not using an ECM why use the relay???? Just delet it

 

[TURNA]

So this is the brown wire coming out of this relay.




View attachment 116384

yes

 

[Bonnewagon]

I know it is supposed to take around 25psi to activate the low pressure switch. But the last time I filled a system from scratch all it took was 2 ounces of R-134 to engage the clutch.

 

[565bbchevy]

IMO if your not using an ECM why use the relay???? Just delet it

So you are saying just eliminate the relay and that plug since they are ECM related?

 

[hoffa65]

So you are saying just eliminate the relay and that plug since they are ECM related?

Yes
Why have it in the circuit when it does nothing anymore, just something to fail later on.