radiator fan issues

[matt999]

Hey guys,

Perhaps some sparkys can help. The radiator fan on my mk3 stopped working. So tested the thermoswitch by bridging the lug to close the circuit, and the fan doesn't work. I checked the fuse 19 and that's fine. I then tested the fan by running 12 volts straight from the battery, and the fan works fine.

So howcome bridging the thermoswitch isn't working? As far as I'm aware there's no relay for the fan. So could there be a fault in the wiring perhaps, somewhere between the switch and fan, or 12v supply and switch?

[JohanBJF]

Hey guys,

Perhaps some sparkys can help. The radiator fan on my mk3 stopped working. So tested the thermoswitch by bridging the lug to close the circuit, and the fan doesn't work. I checked the fuse 19 and that's fine. I then tested the fan by running 12 volts straight from the battery, and the fan works fine.

So howcome bridging the thermoswitch isn't working? As far as I'm aware there's no relay for the fan. So could there be a fault in the wiring perhaps, somewhere between the switch and fan, or 12v supply and switch?

Have a look at this website, you never know
http://www.nairaland.com/1444713/radiat ... ng-problem

[joggiep]

Do you have a Multimeter ?

[matt999]

Not on me, but my brother's got one that I can get hold of this week.

PS, in the mean time tonight I'll be rigging up a relay and remote switch so I can switch on the fan manually when I'm sitting in traffic!

But can you confirm that the test I dis by bridging the thermoswitch was correct, and the fan should have worked by doing this?

[joggiep]

What you have done basicly tells you the following :

Fan is working.
Either no power getting to the termo switch or no power going from the termo switch to the fan.

Best is to get a multimeter an test if you get 12V between earth and the power "in" cable.
if you do then chances are the thermo switch is buggered.
If there is no power then you'll need to trace the wire back to it's relay and then to the fuse.
Also worth making sure that you get 12V at the fuse.

[matt999]

This makes sense, thanks joggie!

I'll give that all a test this week...

[cli 16v]

You can pull out the connector to the fan switch that sits on the radiator. It should be a three pin if the car has an aircon, bridge that and if the fan comes on then the switch is popped.

[Rmunetwa]

Does the fan bridge test apply to golf 5 as well? Cli 16v

[panic-mechanic]

no golf 5 you have to use vcds and in output tests start the fan. it is controlled by the management, not a physical switch anymore.