Looking for a thread about A/C with Power FC. I'm trying to get my A/C ready for the summer...Any help??? On my Power FC speed 1 is working speed 2,3,4 don't turn on.. Thanks

 

Did you check the PFC forum?

https://www.rx7club.com/showthread.p...r+conditioning

 

From Dale Clarks PFC FAQ

(web site seems to down again)

3f. My AC doesn't work on certain speeds. How do I fix it?

This is a common problem with the PowerFC. There's been a great deal of speculation
over the years as to the hows and whys of this problem.

First, a little background. FD's in the US came with 2 air conditioning systems - MANA
and Nippondenso. MANA systems were in all non-Touring cars - these systems were
installed at the port when the cars arrived in the US. The system was designed and
supplied by MANA (Mazda North American Operations). Reasons why seem to be due
to extra taxes or cost for bringing the cars over with air conditioning already installed.
Touring models came from Japan with the AC system already installed - the system was
made by Nippondenso, hence the name.

There are some subtle differences between the two systems, and it's believed that the
PowerFC will work better with the Nippondenso AC system, as that's what all the
Japanese cars have and it was designed for the Japanese market.

The glitch seems to primarily be on certain fan speeds. Some people have had success
with pulling the fan speed **** out of the car and cleaning the electrical contacts. The
PowerFC seems to be more sensitive to resistance that the stock ECU, and dirty contacts
will increase the resistance in the circuit.

There have also been some fixes involving bypassing the ECU's control of the AC. This
can be a problem, as the ECU is designed to shut the AC compressor down at high RPM
or high load to prevent damage. You take the AC input and output wires going to the
ECU and splice them together – this takes the ECU out of the loop for AC control.
Problem is the AC will not disengage at high RPM or load, which will bog the car down
and could also harm the AC compressor, as it’s not designed to be running at 8000 RPM.

It’s really pot luck if your AC will work perfectly with the PowerFC or not. My car
works 100% - all fan speeds, everything works just like normal.

 

move the fan speed selector to 3 and 1/2 and giggle it. Look at your sensor check under etc. of your commander.