Thanks to this website and many other write ups, I was able to finish my swap! And NOW need 1 more thing. AIR CONDITIONING. I didn’t think it would be that complicated. But I have run into a dilemma. I have researched that I need to trick the ECU. But no where would give a hint how to trick the ECU. Maybe Im not understanding the AC wiring operations well enough…
Here is my problem:
I plumbed with custom hoses and used the 1uz compressor. My AC switch inside will not activate the compressor clutch. When I do override and add 12v, the clutch will engage. This has allowed me to add R134 and allow me to have cold AC when IDLE only… BUT when on idle, I am not able to drive it, as it seems like the tranny will not operate correctly. Which I have found it may be related to the AC. When idle-ing, it is very low, it is NOT idle-ing up.
When testing the wire to clutch I get 11.8v constant with or without the AC switch.
My research has led me to believe the 1uz has its own AC ECU, which gathers information about the pressure switch and so forth.. Once enough info is gather, it then sends a signal to the ECU, which in turns send the signal to the clutch and idle up valve.. My ECU only has 2 wiring related to the AC; AC & ACMG. AC goes from ECU to the AC ECU and ACMG goes from ECU to clutch.. Im assuming the AC wire sends info from AC ECU to ECU. THEN the ACMG would send the signal to turn compressor clutch ON/OFF.. I could be wrong, please help clarify. It’s a 92 Lexus SC400 USA engine.. Thanks in advance.
Here is my problem:
I plumbed with custom hoses and used the 1uz compressor. My AC switch inside will not activate the compressor clutch. When I do override and add 12v, the clutch will engage. This has allowed me to add R134 and allow me to have cold AC when IDLE only… BUT when on idle, I am not able to drive it, as it seems like the tranny will not operate correctly. Which I have found it may be related to the AC. When idle-ing, it is very low, it is NOT idle-ing up.
When testing the wire to clutch I get 11.8v constant with or without the AC switch.
My research has led me to believe the 1uz has its own AC ECU, which gathers information about the pressure switch and so forth.. Once enough info is gather, it then sends a signal to the ECU, which in turns send the signal to the clutch and idle up valve.. My ECU only has 2 wiring related to the AC; AC & ACMG. AC goes from ECU to the AC ECU and ACMG goes from ECU to clutch.. Im assuming the AC wire sends info from AC ECU to ECU. THEN the ACMG would send the signal to turn compressor clutch ON/OFF.. I could be wrong, please help clarify. It’s a 92 Lexus SC400 USA engine.. Thanks in advance.