C30 Faulty AC Switch

ab1Al @ab1 Melbourne
edited November 2020 in Troubleshooting

On my newly acquired c30 I have noticed the fan likes to come on after it's been sitting for a while and it's not hot I would imagine. Perhaps this is normal function I scanned it for codes and nothing came back. No over heating



  • Never saw that happen on our C30. In fact it has never come on while the engine is switched off...sounds odd to me.

  • Do you have any more details on when the fan is active eg: engine/A.C on/off, what speed fan is running at?

    Fan modules are a common issue on some of the modern volvos (xc60/70/90) but not so much on the p1.

  • ab1Al @ab1 Melbourne

    sorry i mean when i just turn the car on after its been sitting. the engine is warmed up but say i come back to it an hour later and start it the fan will come on full blast for about a minute or so then switch off. AC switched off

  • That definitely doesn’t sound normal...but no idea what it could be.

  • ab1Al @ab1 Melbourne
    edited October 2019

    it seems to operate completely normally aside from startup and besides a cold start.

  • Far out theory...I’m pretty sure when you start the car the A/C compressor comes on for a short time even if the A/C switch on the dash is off (I assume maybe its to circulate the coolant and keep things lubricated?) If one of the A/C pressure switches that controls the cooling fan speeds is defective, it could cause the fan to come on for a short period after start-up. Maybe let the car get up to temp, then hit the A/C switch - does the cooling fan come on high immediately? If so, that could indicate a problem with one of the A/C sensors. Just a theory and could be totally wrong.

  • ab1Al @ab1 Melbourne
    edited October 2019

    you could be completely on the money there. as i do hear the ac or what i thought was ac click on even with it set to off on startups.

    i shall investigate further

    i did notice that the a/c performance didnt seem particularly strong given its a modern vehicle. perhaps these two are interconnected

  • The AC on our C30 is awesome, so if yours isn’t great, I’d be looking there as a start.

  • TzantushkaTrent @Tzantushka E. suburbs - Melbourne

    According to VIDA that's what happens to ensure the A/C system is cycled even when the A/C is switch off from the dashboard.

  • ab1Al @ab1 Melbourne

    okay interesting. would that mean the fan function is normal or it still implies there may be an issue with one of the pressure switches

  • I think @Tzantushka was just confirming my suspicions that the A/C compressor cycles on for a short time when the car is started. Your electric cooling fan on the radiator should not run at a high speed at any time unless it’s getting a signal telling it the engine is hot. I think you still have a problem. My C30 the A/C compressor runs for a short time after starting the car (maybe 5-10 seconds) but I never hear the radiator fan come on unless I’m in slow traffic with the A/C on.

  • ab1Al @ab1 Melbourne

    i spoke to a friend with a c30 2.4i and they said they have the same thing so we must both have the same issue. a faulty a/c switch seems like the likely culprit

  • i got my ac regased and unforuntaely it did not restore its power. the a/c clutch appears to cycle very quickly which seems to me that there is either a blockage or faulty pressure switch. im guessing the latter.

    does anyone know the location of this switch. i suspect changing this will solve my fan issues.

  • Pressure switch is to the right of brake booster/reservoir.

  • Is there one on the compressor I spoke to a mechanic and they said theres one on the compressor that needs the gas to come out again

  • Did they tell you what the pressures were when the A/C is running? I'm pretty sure there isn't anything on the compressor just the electrical connector for the clutch.

    They may be confused with some of the other Volvo models that have a suction control valve Ill have a look at my c30 tomorrow

  • im not sure he just said that its the most common failure in the ac system. volvo mechanic so id assume he knows what hes talking about

  • Not all Volvo mechanics are equal

  • Well that is slightly relieving. Is that off a t5?

    You wouldn't happen to have the part number by any chance? I'll order it asap

  • Which part numbers do you want Pressure switch or compressor or both

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