I have an nb fitted with air con & it has 2 radiator fans. It was smelling a bit hot recently so I ran it for a while to see if the fan came on. It did after a while but it was the left hand one that i always thought was the air con one. Not the smaller one on the right which remained off. Could somebody clarify which is which please.
The one on the drivers side is the air con one, the one on the passenger side is the normal engine one.
Great, thanks for that. What was confusing me was that when I turn the air con on it is the passenger side one that comes on, the same one as when the engine is hot. The drivers side one never seems to come on at all.
That is standard behaviour for the fans.
When aircon is turned on, assuming no pressure issues, etc, the aircon fan runs and the compressor actuates.
The cooling fan only comes on when the engine is starting to overheat.
If your cooling fan is running all the time you have a real problem!
Leave the engine running for 15+ mins at this hotter time of year and you will see the cooling fan cut in. I do this every year or so just to be sure that it and its associated sensor are working correctly.
With the air con turned off the passenger side one as you say comes on after about 15 mins so is working correctly in that respect. What is throwing me off the ball a little is that it is this same fan that comes on when the air con is turned on. The other one (drivers side) never seems to do anything.
Yeah, but that’s not the behaviour Phoenix22 is seeing. The AC fan never runs.
Engine gets hot: radiator fan runs. Turn on AC: radiator fan runs. That confuses me.
Check the relays on the plastic panel behind the passenger side headlamp, I’d guess the wiring has corroded through. Coincidentally enough, it’s a topic that’s covered in the Owners Club magazine this issue.
My apologies, dropped in on the thread without comprehending completely.
Just read the June edition of STHP and what a timely article 
A good chance that a relay wiring issue is suppressing aircon fan operation which AFAIK should be immediate when aircon turned on.
I hope the OP checks this out and gets back to us.
Brilliant. Fantastic response. Just had a look now & the red/black wire to the nearest the front relay has come off. Will re do that connection & let you know what happens.
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Have a good check of the other wires too, give them all a wiggle and makes sure that they are sound.
Just had a little wiggle of the rest of the wires& none of them are very happy. This little lot should help fill some time that is left on my shielding incarceration.
The wires are regrettably all in a similar environment. If one has corroded, it is very likely that some of the other relay wires/connectors have too; don’t you think?
Yes, it looks like I will have to re wire both relays.
I will send folk out for a couple of new relays tomorrow, get them in & report back. These are both now off yet interestingly the engine cooling fan still comes on when the air con button is pressed.
One relay is for the A/C fan and the other for the compressor clutch. I’d keep the relays, cut the plugs off the wiring harness to find good wire then crimp insulated female spade terminals on, blue ones for the thick wires and red ones for the thin ones.
OK, will do this. Many thanks.
Re-done all the connections & all working perfectly now. Cheers for the advice guys.
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Good work! Thanks for the feedback.