Driving car with A/C deactivated?

Lokiel · Postby **Lokiel** » Tue Dec 11, 2018 11:01 pm

I've made some modz that required me to relocate the AC cannister and hoses so some of the hoses are disconnected and the A/C has been de-gassed.

My "mad-Google-skills" have led me to believe that I can drive the car with the A/C belt still connected if I remove the 7.5A A/C fuse under the dashboard.

Can anyone confirm this or if I need to do anything else to allow me to drive the car until I get the A/C repaired?

greenMachine · Postby **greenMachine** » Wed Dec 12, 2018 7:59 am

The A/C is mechanically inactive until switched on. There is an electrically operated clutch in the compressor that responds to the switch, until that switch is 'on' the pulley just freewheels so the compressor is stationary.

Pulling the fuse will guarantee the compressor doesn't operate (in the event someone forgets and switches A/C 'on'), but is really just a backstop.

However, there may be other things that use the A/C circuit for power, if there are any you would lose them if you pull the fuse.

:mrgreen:

Postby **NitroDann** » Wed Dec 12, 2018 8:20 am

100% that ^

hks_kansei · Postby **hks_kansei** » Wed Dec 12, 2018 10:07 am

greenMachine wrote:Pulling the fuse will guarantee the compressor doesn't operate (in the event someone forgets and switches A/C 'on'), but is really just a backstop.

That's not even a concern, since the AC system (on the NB) has a pressure switch, so that if the gas is gone it wont activate the compressor clutch, regardless of AC switch position.
the ECU also doesnt change by the switch (unlike the NA where if you press the AC button without an AC compressor present the idle jumps up)

My AC has no gas, and the switch doesnt do anything except light up.
Only way to kick the compressor on is to use a jumper wire and manually bypass the pressure switch.

So yeah, dont even bother removing the fuse, just vent the system and drive like normal.

Lokiel · Postby **Lokiel** » Wed Dec 12, 2018 4:00 pm

Thanks for all the advice - will only be driving at night while I have no A/C here in QLD.

ianoz · Postby **ianoz** » Wed Dec 12, 2018 9:15 pm

Doesn't sound like you need to worry about it, but the 7.5A AC fuse also supplies power to the coils on the blower-fan relay and rear-demister relay, so you'd loose them too.

If you're worried about it, pull the "AD Fan" 20A fuse instead. That powers the magnetic clutch.

greenMachine · Postby **greenMachine** » Thu Dec 13, 2018 8:15 am

At 20amps, that is more like what I imagine the compressor clutch would require.

Interesting about the fan relay, I have noticed that the A/C light will not come on until the HVAC fan switch is 'on'. Because in the heat of the moment I have been known to inadvertently hit the A/C switch when changing gears, leading to a track session with the engine powering the A/C, my marshalling area check includes 'A/C off, fan off'.

:mrgreen: