Hello all...

I'm trying to solve faulty aircon on our 2010 1.6 vct but I'm being stumped by the operation of the fan. If anyone can help please?

It had zero gas so probably has a leak. However, a re-gas showed the system does cool the air but only when moving, ie. there is air flow through the condenser. With aircon switched on the radiator fan runs but only on a very low speed, not enough to cool the cabin air. When stationary you get ambient air temp. So aircon triggers some fan, but not enough. The fan running is definitely connected to the aircon being switched on, it is instant with switch on and runs for 30secs after switch off.

I don't know if this is relays (more than one for different speeds?!), the fan itself, or maybe the fan control module. Can anyone suggest how to test/discount different parts?

Many thanks!

10 hours ago, Jim1.6 said:

the radiator fan

Do you mean the the aircon/heater fan (in the heater assembly in the cabin) rather than the radiator fan (under the bonnet behind the radiator)?

I mean the radiator fan, on the radiator. It spins on a low speed, too low to provide adequate air flow to cool the aircon when stationary. 

I remember from a previous Fiesta that the radiator fan makes a lot of noise when the aircon is on, because it's running fast all the time when aircon is on or the engine coolant is over temp. This one isn't doing that. 

I'm hoping someone can have a stab at a diagnosis if they've heard of this issue before.

First test you can do is putting 12 volts directly to the fan motor, bypassing everything else.  That will prove whether the fan can run at full speed or not.  (Obviously keep hands and loose clothing well out of the way!)

If the fan motor is proven good then I'd suspect the fan module to be the issue here.

Just put 12v to the fan and it powers up just fine. 

I was expecting to see the module at the bottom of the fan but it doesn't have one... just a 2 pin plug. +ve and -ve on these terminals powered the fan.

So where is the module? Or am I barking up the wrong tree?

According to another thread, I have system B... relay R1 but no R7, no fuse 2, fuse 3 40A.

Maybe the speed the fan is running at with the ac button on is all I should be expecting. It's pushing a lot of air for sure. But that still doesn't explain why it's not cooling the aircon down.

Maybe the condenser is blocked?

Take the car to KwikFit and get it regassed. They offer a money back guarantee if the aircon temperature doesn't drop by 'so many degrees' after being serviced.

 

Money back if it doesn't drop by 10%. Thats only a couple of degrees. However, a regas won't help as I've just had that done and have proved the system works when on the move, but the fan can't do it when stationary. 

Previously had corroded connector on the cooling fan which caused intermittent operation. New connector and labour was £60

I will check that out. However, it seems like too much of a coincidence that I can go for roundabout after roundabout, up to speed then down again, and the ac is cold then ambient again and again.

I'm stumped. But I have a new condenser to fit, so I guess we shall see what happens!

My fan only runs on the slower speed when AC is switched on but the AC cools fine whether stationary or moving.

This has been diagnosed as a knackered compressor. Or a very lazy one at least! Increased engine rpm gave just enough from the compressor for the aircon to work OK, at idle it's not giving enough.