AC System Operation

Well, as a few of you know, I've LS Swapped my tacoma, and now it's time for AC. Ive been committed to the idea of just running the AC Compressor clutch on a simple switch and relay, at the risk of completely freezing up my evaporator due to the lack of pressure or temperature sensors. Ive been tossing the idea around to put some of these temp or pressure switches in, but I dont know what pressure or temperature the evap core starts to ice over at.

Are there any AC geniuses here?

 

Someone in the GX swap thread said they could possibly make a module for the AC to work in that thread. Maybe see if that guy can help you?

I’ll see if I can find the post or tag the guy.

 

This guy
https://www.tacomaworld.com/threads...-powertrain-swap.766665/page-42#post-29016932

 

The problem is I dont have any of the pressure sensors anymore. Tricking the AC amplifier into thinking there is RPM and ECT is one thing, but it actually needs system pressure to deactivate that compressor when required.

 

Then I have no idea.
I don’t do AC. Or transmission.

Maybe @Dm93 has an idea.
He’s the only guy I know on here that does AC work.

 

High pressure cutout on the liquid line is typically set around 450 psi.

Most expansion valve systems use an evaporator temperature sensor/switch because its much more accurate than using a low pressure cutout for freeze-up protection, typically they are set to cut out around 34F and on around 37-40F.

 

Does the 2nd gen evap have a temperature switch I'm able to utilize?

 

There's a thermister on the evaporator but you would need some kind of electronics to use it if your not going to be using the stock A/C Amplifier.

 

I’m using the stock amplifier, but because I don’t have an RPM signal or ECT signal or any of the pressure switches I doubt it’ll engage the compressor. Was planning on keeping it to run the blower motor and servo motors and blend doors, and have a secondary button for the compressor

 

I just had a thought, you could use one of these cheap temp controllers for freeze protection.
You may even be able to use the stock thermister if the resistance is the same or close.

$12 LM YN DC 12V Digital Thermostat Module -58℉ to 257℉ Fahrenheit Temp Display Temperature Controller Board with 20A Relay Waterproof Sensor Probe Dual LED Display Red Blue

https://www.amazon.com/dp/B076Y5BXD9?ref=ppx_yo2ov_dt_b_product_details

 

Thats actually brilliant! Do you have the pinout available for the two connectors going into the AC Amplifier?

 

I can grab it later.

 

Here you go.

 

Thank you sir!