ZeroBanger

Ok...well I think this works I have not tested it long term yet. This is *REALLY* retarted and most of you will probably laugh but here we go. My AC never worked on 3, which was fine for me cause I would use that to turn the fans on hi. I got my engine replaced and now it doesn't work on 3, 4 and its starting to get flakey on 2. This is not acceptable.

Again, this is retarted but I would turn the a/c **** to the 2.5 position (between the 2 and 3) and it would blow like 3, but the AC would work. I then put it on the 3.5, and again, that would work exactly as 4 is supposed to.

I have researched and could not find anyone using this fix. Maybe others have figured this out, maybe not but hey it seems to have worked for me.

Now I have not tested this long term. I Just figured this out now and it was the only way to get it to work.

Eggie

Are you sure that the PFC is causing this and not the blower resistor?

ZeroBanger

Never had a problem with my stock ECU. I ran that for like 6 months. As soon as I got a power FC, # 3 didn't work. # 4 went in and out.

David

Eggie

Sounds like the PFC all right.

cewrx7r1

iTrader: (2)

Eggie,

The PFC has had this bug since 2001. Acts like an internal floating ground problem.

racerxrx7

I don't think it's your PFC, mine stop working before I did any modifications. After my modifications it still acted the same way. I think it's just the resistor that it's broken.

ZeroBanger

whats the resistor? And why does it work with my stock ECU and not my power fc?

AbadR1

iTrader: (1)

Hehe I need to know also. Thanks

DChan415

Sounds like your fan switch to me

rynberg

It's not the switch, it's some interaction between the car and the PFC. I tried the same trick on mine and it worked....

ZeroBanger

Tyler:

You should have seen your face when you saw that a/c sensor reading on when we tried my trick, LOL. That was classic!!!

everyone else:

If you have the ac problem grab your power FC put it on sensor to monitor the a/c, for this example I will assume #4 does not work. Take the **** and SLOWLY turn it and watch the PFC, when the sensor lights up your AC will be working. There is a sweet spot and just placing it midway between the two settings will not work. After a while you can figure it out without looking at the sensor.

forcefed1

for a year now I have had a similar problem. my AIR CONDITIONING worked in blower 1 and 2 but not 3 and only a bit in 4.

Now after a good look at the wiring schematics, I have come up with the best work around yet.

For the last year what I did was run an auxilary switch to run the compressor. That was a pain as I also had to turn the dash A/C switch on to get the cooling fans to work and the Idle to rise. This way also overrode the thermo switch on the evaporator that cycles the A/C when your are not running it full blast. and the compressor could be on no matter if the blower fan was off or any other condition.

Not anymore. what I have done now is basically run the dash Air Conditioning switch to turn the compressor on.
Basically what I did is tie the signal, used to turn the engine cooling fans on when the AC is on, into the compressor relay.

This signal works best as the evaporator thermo switch, blower setting, and Dash A/C switch are all included in the logic to run the compressor. Best part is was real real easy and only takes 15 min to do.

All you have to do is cut one wire and splice it to another at the ECU. You need to cut the output wire from the PFC to the compressor relay (the wire the PFC is not controlling as it should ) and splice it to the signal wire going into the PFC used to raise the IDLE when the AC is on. Do not cut this second wire!!! tap into it's signal. Ill post the wiring diagram and show you the location and colors of the wires you need to work with.

The only AC on logic not taken into account with this mod is during engine starting and heavy acceleration. (here the PFC would have disabled teh AC compressor briefly and now it will still run)
all other times the AC will operate as if your stock ECU is running it..... HOWEVER. the engine IDLE RPM will only be raised to your A/C setting RPM when the PFC would normally have been running the compressor (i.e. look at the monitor switches screen on your commander and determine what blower setting it does work at)

Now Ill try and post the Diagram to show you the wires to splice.

forcefed1

looks like Ill have to post the diagram later. check tomorrow

Herblenny

iTrader: (13)

I am very interested in this.. I have installed my PFC about 5 months ago and last weekend I turned my AC for the first time.. And it didn't work.. I'm assuming its the PFC.. Hope it is..

forcefed1

well the diagram won't attach so Ill tell you how to find it

go here
http://www.iluvmyrx7.com/

then go to 3rd gen
then manuals
then 93 factory service manual
then download the wiring diagram
look at page z 68
what you are basically doing is cutting wire 37 yellow and black wire on the ECU connector #4 pin 6 on the bottom, and splicing it into wire 36 violet wire on the ecu connector #4 3rd pin from the right on the top. I wish I could show it better.

to help with the wires at the connector, the connector #4 has 22 pin locations and it the bottom most connector plugging into the ECU

if you hold the connector with the wires going away from you, lockin tab on top, the wire to cut is the yellow wire with black stripe on teh bottom row pin 6 from the left.

the wire to splice that cut wire into is the violet wire pin 9 from the left of 3 from the right on the top row of pins.

I hope this helps...
having the thermo switch tied into my AC compressor logic has made an improvement. the compressor now cycleds to keep the Evaporator at the optomum temp based on cooling load to the evaporator.
and when I shut off teh AC switch or blower motors my compressor os not running without me knowing.

for anyone having problems this 15 min fix should do it.

RX7 RAGE

iTrader: (22)

My PFC doesn't work on setting "3" either. =(

forcefed1

looks lik you should do my simple mod then

ZeroBanger

This mod you are refering to has been discussed many times. The problem is that the ECU does not shut down the compressor when under heavly load.

Its not a bad thing if only setting 3 on the power FC doesnt work, you can use 3 to turn your fans on a few minutes before you park your car.

cover8

I also have the same problem....A/C works great on 1 and 2 but not 3 and 4 although the fans work on all settings.

Herblenny

iTrader: (13)

O.k.. Sorry to bring this topic up.. So, my question is.. when you remove the power (battery terminals) does PFC relearn or anything?? because My AC was working on 1,2, and 4 but now it doesn't work it all.. Its driving me nuts.. And a friend haven't had his ac worked since his PFC purchase.. We checked his car and when I hot wired the clutch, the ac worked fine.. so, I'm thinking its PFC....

also, if you hook up the switch to the AC clutch, would it over compress if you leave it on?? doesn't pressure switch shuts the clutch off when its over pressurized?? Where can I hot wire for the clutch???

RX794

OK, this is really weird because my A/C works in every fan speed setting with my PFC. When I did the motor over, my car had a stock ECU in it, then I went single, etc., and put a PFC in it. It works the same as the stock ECU did, the only difference is that the compressor won't release under full throttle like the stock one, which is no problem. What I think is really the cause of this problem may be weak or bad grounds, check all your grounds by the ECU mounting point, and clean all the grounds by the A/C wiring, see if that helps.

Herblenny

iTrader: (13)

I just did the battery relocation and one of my ground is to PFC surround.. Hmm.. I will double check on few things.. Also, I have never got that recall thing done.. I think its the AC recall.. would that make any difference??? I'm afraid to take my car to the dealer..

cewrx7r1

iTrader: (2)

If you use the ECU bypass A/C fix, true the A/C will not turn off like stock when you go full throttle.

So what is the problem? Take your right index finger and just push off the A/C switch when you race.

I think you should be capable of doing that!

RX794

I don't have the "ECU bypass A/C fix". I wasn't complaining about the A/C compressor not shutting off by itself on full throttle, I was just stating to everyone that the PFC doesn't shut off the A/C compressor on wide open throttle like the stock ecu does. This applies whether you do, OR do not have the "ECU bypass A/C fix".

Herblenny

iTrader: (13)

I just want to double check on this.. IS this the ECU bypass??? Just wanted to make sure..