Thread: Air Con Thermo fans

the fans should go on with the compressor. First thing to check is the fans themselves by hot wiring to the battery.
there is also a switch on the thermostat which turns them on at 105c.
regards Philip A

Thanks, I was going to put power straight to them to see what happens.

So they are switched by the coolant temp , not by anything to do with the air con side ?

Cheers Ean

Originally Posted by Ean Austral

Thanks, I was going to put power straight to them to see what happens.

So they are switched by the coolant temp , not by anything to do with the air con side ?

Cheers Ean

No as Phillip has said they should come on with the air con compressor switched on.
and they will also come on if the normal coolant temp exceeds 105 degrees as a backup to the viscous fan.
I have had mine not working and found that the brushes on the motors were worn down.
So hardwire them to the battery to check that they actuallly run before you go Hunting for any other problems..😋

So they run no problems with power direct from the battery . Fuses 8b & 9b which according to the diagram are the fan fuses are fine.

I guess next is find relay 9 in the spaghetti junction of relays under the dash .

Any other suggestions. ??

Cheers Ean

And also once going,check they are going the correct direction.

I came across a vehicle last week,the thermo fans were going backwards

So found that the fan relay was missing but after fitting another they still dont seem to run. I have read a fair bit and it seems they switch from the pressure switch on the top of the dryer on some models and on others they are started by the temperature switch.

I am thinking of just powering them straight from the compressor , does anyone see an issue with this ?.

Cheers Ean

Originally Posted by Ean Austral

So found that the fan relay was missing but after fitting another they still dont seem to run. I have read a fair bit and it seems they switch from the pressure switch on the top of the dryer on some models and on others they are started by the temperature switch.

I am thinking of just powering them straight from the compressor , does anyone see an issue with this ?.

Cheers Ean

Never without a relay, but of course you can trigger your own relay from the compressor clutch.

Originally Posted by bee utey

Never without a relay, but of course you can trigger your own relay from the compressor clutch.

Yes, I was going to activate the fan relay from the compressor clutch .

Cheers Ean