Electric engine fan query..

[Tonka]

Hi there. My leccy engine fan hasn't worked normally for a while. I replaced the switch which screw's into the thermostat housing, but it rarely comes on, only occasionally, then when I turn the engine off and remove the key it goes off!

Anyone got any ideas? I guess first thing is to replace the switch, don't really want to pay Roughtrax £30+ for one...
If anyone can take me through some testing I have multi meters etc.... Thanks!

[tweak'e]

need a few details.
what model surf?
which fan? (some have two fans in the front)
which switch/sensor in the thermostat housing? (some have overheat sensor, some may have a low water sensor)

[Tonka]

need a few details.
what model surf?
which fan? (some have two fans in the front)
which switch/sensor in the thermostat housing? (some have overheat sensor, some may have a low water sensor)

Hi, sure thing, many thanks for the help. It's a1992 LN130 2.4 diesel. SSRX if I remember correctly.
The fan is the one at the front bolted to the rad, the switch is screwed into the thermostat housing, or the block, can't remember which, but where it can sense the coolant temperature. It's on the right as you look at the engine, near the rad. The leccy fan used to stay on after the engine was switched off, but now doesn't.

[Tonka]

Update....

So I just tested the fan by removing the lead from the sensor switch on the thermo housing and it comes on. So it is working, but doesn't seem to come on in normal use. So either the sensor is duff, or there's another problem.

I've checked all the fuses I can find and they all seem ok.....is there a solenoid to look at?

Many thanks

EDIT: The fan does stay on (obviously when it's hot after a run) when the ignitions off and keys are out doesn't it?

[woodwarm]

Electric fan on my 2.4 never on at normal temperature range.

I thought fan only operated at higher temp 100 +

Do you have overheating problems or low coolant levels ?

Transmitter located in thermostat housing

[Tonka]

I do have a coolant leak yes and I keep having to top it up. So, as I don't have the time to sort the leak out I need to make sure the fan is working.

I have heard it working recently when I pulled off the motorway into a petrol station, but as soon as I turned the ignition off it stopped. I'm sure it's not supposed to do that is it?

[tweak'e]

its an overheat fan.

would have to test the sensor because i think there is two versions, one is temp sensor the other is coolant level sensor.
i would not be driving it with a coolant leak, it only takes a piddly small amount to drop the level down to "crack the head level".

[Tonka]

its an overheat fan.

would have to test the sensor because i think there is two versions, one is temp sensor the other is coolant level sensor.
i would not be driving it with a coolant leak, it only takes a piddly small amount to drop the level down to "crack the head level".

Hmm....not sure on this, but this one is definitely a temp sensor as when you unplug it the fan comes on....

It's had a small coolant leak for years, I just check it really regularly.......

[woodwarm]

its an overheat fan.


i would not be driving it with a coolant leak, it only takes a piddly small amount to drop the level down to "crack the head level".

Viscous fan does all the cooling required.

Make a coolant system pressure tester & fix the leak (assuming external leak)

[tweak'e]

Hmm....not sure on this, but this one is definitely a temp sensor as when you unplug it the fan comes on....

It's had a small coolant leak for years, I just check it really regularly.......

i think the low level sensor does the same. i came across it in the parts book when i was doing mine. unfortunately mines long gone so i can't test it.

[tweak'e]

Viscous fan does all the cooling required.

Make a coolant system pressure tester & fix the leak (assuming external leak)

whats that got to do with my post?

[Tonka]

Viscous fan does all the cooling required.

Make a coolant system pressure tester & fix the leak (assuming external leak)

Many thanks, how do I make a pressure tester? I'm thinking I'd need to remove the thermostat, drill a hole in an old rad cap, fit some sort of pump etc?

[woodwarm]

whats that got to do with my post?

Was agreeing with you,ref loss of coolant & "crack the head"

[woodwarm]

Many thanks, how do I make a pressure tester? I'm thinking I'd need to remove the thermostat, drill a hole in an old rad cap, fit some sort of pump etc?

Remove the overflow pipe at expansion bottle.Use a bicycle pump with a small adapter eg cut out a valve from an inner tube. insert valve into pipe leading to radiator cap & pump a few times,only requires a few psi.

pressurizing should reveal leaks from hoses, rad etc.

[tweak'e]

Was agreeing with you,ref loss of coolant & "crack the head"

that makes more sense, especially when i'm half asleep!