I just got a PFC at rotary performance and the AC setting 3 wouldn't work. All they did was shake the wiring harness up near the heater and it fixed it. They said they do this on every FD thas has the AC problem where some settings don't work, and it fixes them everytime. Kind of strong, but it works. They said the issue was due to the PFC being more sensitive to grounds or something. Just thought i'd share.

 

Really? If it's just a case of poor grounds, seems like you could add an additional ground and have it be solid/reliable.

If that actually works, that's pretty cool .

Dale

 

From what I've been told, the problem is the stock ECU starts the compessor when the voltage is below 3 but the Apex'i doesn't until it gets below 2. This is on the "AC Request" pin. A diode in series with this wire should fix the problem. Yes, as soon as I put in the Apex'i, my compressor wouldn't start on 3 and 4 (but runs fine on 1 and 2). The fan speed resistors appearantly load the system differently and affect the voltage. Took a while for me to notice, as AC isn't needed here very often. I'm told it's a contact problem on the "thermoswitch" behind the glovebox. Fixing it by wiggling that harness adds confidence in this prognosis.

 

Ever since I put in my PFC I have had no A/C. I can jump the relay but the compressor is on all the time, not good.

 

then just yank on the harness a couple times and it should work. Seriously...my setting 3 didn't work. They yanked on the hanress and it worked.

 

Where exactly did they shake it? Under the dash?

 

yea...under the dash. More specifically, its the harness located near the heater core under the dash on the passenger side. Just reach your hand up past the ECU and a little more towards the center of the car and you should find a harness.

 

its the blower motor relay. if this does not work, then you have to take the ac switch apart and run better ground wire. by the way, i was up there at rotary performance with spool up, and saw what they did.

 

do you guys has pictures of it (the relay or the switch) !!! because there are too many of it so....... please let me know thanks

 

I never had to splice the A/C in and out when I installed my PFC!!... it just started working... I just cut the 4 wires and everything worked normally..