A/C Circuit Guru's needed!
 

I'm having some A/C problems and hoped someone could point me in the right direction.

Background info:

90' RX7 Vert w/ TII swap
Purchased the car with working A/C and a Microtech
Swapped ECU to Haltech E8 and A/C no longer works
Using the same logicon that worked 6 months ago


Here's what I have so far

- I went through the Microtech wiring diagram and undid all wiring required for A/C on that system ( put A/C wiring back to stock at the relay and AC-02 connector )

- Haltech work around for A/C and boost control bug performed - Load default_e8.map and setup input and output. I was unable to get a signal from the A/C button even with the "fix".

- Haltech is not receiving a signal from the logicon when A/C button is pressed and illuminated. Tried both my "tuned" map and the default map as recommended by Haltech and those who have gone through it on 7club.

- Compressor shows ground between connector and pump.

- I'm not able to properly activate the A/C main relay which causes no signal to go to the compressor on A/C button depress.

- I've tried 2 A/C relays and still get 12v on the red/yellow wire which is supposed to read 0v when A/C circuit is functioning properly. All other relay posts are normal.

- Inverting the input ( AC request ) from the Haltech turns the A/C system on but will not allow me to turn it off.

- When the A/C is on I can see it flow through the glass. There are bubbles present. I understand this is something that would indicate a low level. However, A/C should not activate at all if the level is too low. This leads me to believe I should be able to run the system as is. I will need a recharge soon but don't want to spend the money until I know it will work.

- I'm thinking there's a short between the logicaon and the front portion of the A/C harness. Everything I have read says the logicon should not light up when the A/C button is pressed unless there is a completed circuit.



I need help bad. I've been losing my patience pretty quickly in the heat. Any good next steps you can think of would be appreciated!

Any body have any ideas besides ditching the A/C?

The A/C is wired into your stock ECU. When the car was upgraded to the Microtech the installer rigged the harness so that the A/C would still work. Search the Microtech forum for A/C and you'll see that you can jump two wires on the stock ECU plug to make the A/C work. The ECU doesn't make a difference unless your using it to bump up the idle for the load of the compressor. Its my opinion its not the ECU swap that has caused your A/C issue.

Heres the thread regarding the A/C from the MT forum.

https://www.rx7club.com/microtech-111/got-my-c-working-184227/

Have you checked the pressure to ensure the Hi/Low switch is letting the system turn on?

I thought I had removed all the Microtech A/C wiring. Read about the blue/? and black/? wires in a different thread. I corrected those. I'll go back through that section.

Do you know what I need to probe on the interior harness to trace the signal? I went through the FSM but got a bit overwhelmed.

Thank for the help!

What's up Rat! No. I did look in the glass during a forced turn on though. There are bubbles and I will need a recharge. That shouldn't stop the A/C button signal from reaching the AC2 connector on the driver's side harness next to the A/C main relay though. Am I wrong on that part?