1995 Civic Hatchback with Mini-Me Swap (d15 bottom end, y8 top end)

Having a problem with my compressor not engaging. It use to engage and blow ice cold before I parked the car and did the body work / paint job on it. Now it doesn't engage. I had the shop recharge it for me to make sure there was freon in it and still not engaging. I can jump the compressor wire from the battery and it engages so I know it will engage. I have done multiple tests to the system including swapping ECUs and still nothing. Here is the diagram of tests I have already completed all the way to the bottom of swapping ECUs.




Any suggestions please help.

 

Does the condenser fan run?

 

Yes

 

Does the compressor clutch engage if you jump the A/C pressure switch?

 

No

 

With key in ON(II), if you unplug ECU connector A and then ground the Blk/Red wire at terminal A15, does the compressor clutch engage?

 

Yes

 

Unplug the condenser fan relay and A/C pressure switch connector. Turn key to ON(II). What voltage to body ground do you measure at the Blu/Red wire terminal in the unplugged pressure switch connector?

 

4.71v

 

Replace the ECU.

 

I tried another ECU already and nothing.

 

Your answers to the questions point to a bad ECU. The only other possibility is a bad connection between ECU and ECU connector A at pin A15. Inspect the pins. That's it. Unambiguous.

 

Ill find a 3rd ECU and try that then thanks.

 

Wait! Try this test.

Unplug the condenser fan relay and A/C pressure switch connector. Turn key to ON(II). Ground the Blu/Red wire terminal in the unplugged pressure switch connector. Does the compressor clutch engage?