Air Con Thermo fans

[Ean Austral]

Gday All,

Can someone tell me what activates the thermo fans on the Condensor unit. ? I have the rest of the system which seems to be working but they are not cutting in and the head pressure is rising quite high with the car stationary and they still not activating.

The fuses ( which i think are the correct ones ) are ok .

I havent followed any wiring yet , just wonder whether they are on some sort of pressure system or they just should run all the time.

Thanks and Cheers Ean

[PhilipA]

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

[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

[Bradtot]

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..😋

[Ean Austral]

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

[scarry]

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

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

[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

[bee utey]

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.

[Ean Austral]

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

[PhilipA]

Does the compressor work?
If the pressure switch is US or the system is low (or high) in gas then neither the compressor or the fans will work.

Regards Philip A

[Ean Austral]

Does the compressor work?
If the pressure switch is US or the system is low (or high) in gas then neither the compressor or the fans will work.

Regards Philip A

yes it does , the system works fine , compressor wouldn't cut in until I put enough pressure ( gas) in the system so I can only assume the pressure switch works.

power direct to fans makes them run , fuses are fine , so I can only assume it's a issue with what switches the fans on .

cheers Ean

[DoubleChevron]

yes it does , the system works fine , compressor wouldn't cut in until I put enough pressure ( gas) in the system so I can only assume the pressure switch works.

power direct to fans makes them run , fuses are fine , so I can only assume it's a issue with what switches the fans on .

cheers Ean

I was thinking of removing the condenser fans from mine when I refit everything. I'm running falcon electric fans. I figure the condenser fans just restrict the incoming air compared to the main fans .... If you bridge the fan switch (thermostat housing from memory) do the condenser fans switch on?

If it works from the switch, i'm betting you have a wire unplugged behind the switches inside the car... it sure is going to be fun to find!

seeya,
Shane L.