Keeping her cool

[Oldone]

Hi Peeps
My 1992 2.4 td manual has new head new rad and when the silicon oil arrives an overhauled viscous fan.
It occurs to me I have a seldom-used electric fan (air conditioning) bolted to the front of the rad.
Has anyone any idea of how I could wire this fan to be switched on manually.
Don

[marky]

the fan on the front of the rad is controlled by a sensor on the thermostat housing if you pull the connector off it should spin. it comes on when sender gets hot providing better cooling for the radiator

[Oldone]

Keeping her cool

Hi Marky
I have just been out and found two sensors on the stat housing. One Facing forward and one pointing to the near side lower down Have pulled them off and started engine but front fan does not rotate.
It does not rotate when the aircon is full on either. I think I have a problem.
Don

[Pete]

Hi Marky
I have just been out and found two sensors on the stat housing. One Facing forward and one pointing to the near side lower down Have pulled them off and started engine but front fan does not rotate.
It does not rotate when the aircon is full on either. I think I have a problem.
Don

Don,
This is the fan sensor,
Pete

[da SLUG man]

won't you have to make a circuit with a wire to get the fan on?... jsut pulling the connector will leave and open circuit... um won't it?


(p.s. that's just a guess, so don't quote me!)

[Oldone]

Don,
This is the fan sensor,
Pete

Thanks Pete
The front one must be the temperature gauge sensor.
Don

[marky]

won't you have to make a circuit with a wire to get the fan on?... jsut pulling the connector will leave and open circuit... um won't it?


(p.s. that's just a guess, so don't quote me!)

the 2.4 front fan is for cooling nothing to do with aircon if you pull the front plug off, the fan should kick in

[Vagrant No2]

won't you have to make a circuit with a wire to get the fan on?... jsut pulling the connector will leave and open circuit... um won't it?


(p.s. that's just a guess, so don't quote me!)

Matt
I guess that the sensor when hot makes an open circuit to allow the ECU to allow fan to come on . It is a 'fail safe' system , so that if the sensor fails the fan is on all the time . Better to over cool then allow to overheat .


Rick

[Koi]

Wired mine up to a switch mounted in the dash, wire via a relay for protection. Now I can switch it on when ever I like.

[Oldone]

Keeping her cool

Wired mine up to a switch mounted in the dash, wire via a relay for protection. Now I can switch it on when ever I like.

Thanks Koi
This is exactly what I wish to achieve. One minor problem. I don’t know how yet
Don

[stara]

the easiest way would be a switch in the sensor wire (the sensor is normally earthed) when the sensor gets hot, it goes open circuit, the fan then kicks in, when it cools, it goes to earth and the fan switched off. so by fitting a switch, you can manually open the circuit for the fan to kick in. As the sensor wire is just a wire to earth, then all you need is a simple switch.

[Oldone]

the easiest way would be a switch in the sensor wire (the sensor is normally earthed) when the sensor gets hot, it goes open circuit, the fan then kicks in, when it cools, it goes to earth and the fan switched off. so by fitting a switch, you can manually open the circuit for the fan to kick in. As the sensor wire is just a wire to earth, then all you need is a simple switch.

Hi Stara
Your solution looks good. I might just put a relay in the new circuit to carry the current safely. I have now found my front fan does not kick in when the sensor on the stat housing is disconnected.
The aircon has never worked this is why I thought I might use the front fan. Still looking for a fuse for the fan.
Don

[robnw67]

How will you know?

I recently had a leak in the overflow pipe from the rad to the overflow bottle. As a result the system kept pushing water out of the system and sucking air back in, so I ran quite low on coolant.

The first thing I knew about it was when the electric cooling fan kept cutting in - even though the temperature gauge didn't go above its normal operating point.

So how will you know when to switch the fan on - and will your wiring disable the automatic function?

Rob

[Oldone]

I recently had a leak in the overflow pipe from the rad to the overflow bottle. As a result the system kept pushing water out of the system and sucking air back in, so I ran quite low on coolant.

The first thing I knew about it was when the electric cooling fan kept cutting in - even though the temperature gauge didn't go above its normal operating point.

So how will you know when to switch the fan on - and will your wiring disable the automatic function?

Rob

Well robnw67 I believed the front fan on my Surf only ran with the aircon on.
Now I find the fan has a dual purpose and helps cool the engine as well.
My plan was to leave the manufacture's system intact and switch the fan on
in traffic jams and such.
Since the fan does not work at present my first job must be to mend the little sod. Any information on how the electrics work will be helpful.
Don

[yorkie]

fan

guys,

can any of you offer suggestions as my fan comes on all the time, I have replaced the sensor but still no joy. are there any other checks I could perform. I have already tried removing the relay and yes the fan stops, could this be the problem?.

thanks
yorkie.