ShiftRX7

Hi guys, i know it's a weird period to speak about an A/C issue, but i have been experiencing this since late summer and i haven't been able to address it before.

Here is the matter: when the A/C is on (i.e. A/C button is pressed) and the blower speed is 1 everything works fine, while if the speed is 2, 3 or 4 the A/C doesn't work anymore: the blower actually blows stronger as expected (and as it does when the A/C is off) but the A/C button light turns off and A/C compressor is not engaged anymore.

Any suggestion on what could cause this and things i could check?

Thanks in advance for all your helpfull replies.

Ciao and merry xmas!

G

RENESISFD

iTrader: (13)

Do you have a power fc. This is a common issue and should turn up in a search.

ShiftRX7

Yes i do; maybe i searched with the wrong keywords, i'll give it another shot; weird thing is it appeared at some point in time, years after i installed the PFC.

BTW, just found the right thread, thanks.

IRPerformance

iTrader: (41)

Its an issue with the ecu not seeing the ground for the a/c switch. Look up ac relay fix.

IRPerformance

iTrader: (41)

https://www.rx7club.com/power-fc-for...ng-fix-997129/

bajaman

If it isn't related to the PowerFC installation, I'd look to see if there is a blower motor resistor.
My B2000 did pretty much the same thing, turned out it was the resistor.

JM1FD

iTrader: (1)

The light on the A/C button goes out when you go from fan speed 1 to 2? Then that has NOTHING to do with a PowerFC being installed.

It could be the blower motor resistor, or it could be an issue in the controls in the dash.

Over the summer, I was testing my expansion valve, and wanted to run the compressor without the cabin blower. Easiest way to do that was to unplug the blower motor resistor. It caused behavior similar (but not exactly like) what you describe.

IRPerformance

iTrader: (41)

Actually it can. The issue is the PFC doesn't see the ground so it doesn't kick on the compressor. You could have another issue as well but generally when the blower resistor goes it will only work on high speed. You could pull the resistor and see if its burnt. Sometimes one of the pins break at the solder joint and it can be repaired.

JM1FD

iTrader: (1)

I'm well aware of the PFC A/C ground sensitivity issue. What does that have to do with the A/C button light in the dash? Nothing. The A/C button light works even with the refrigerant pressure switch unplugged. Unplugging that switch completely removes the ECU from the circuit.

IRPerformance

iTrader: (41)

I'm talking about the actual a/c indicator coming on in the sensor check menu. Sorry if I wasn't clear. If the actual orange light on the a/c button isn't illuminating you have another issue.

ShiftRX7

thanks for the input guys.

I'm actually working these days (sigh!) but i'll try to check the resistor pack and the fan speed switch to see if they are in good condition or not; i tend to think this is not PFC related, since the PFC has been there for years and we are speaking of the orange light itself.

season's greetings!

G