Cooling Fan Switch Problems.

Hey mate, got a picture of the 2 plugs?

I had a similar problem about a week ago, plug for the top end didn't fit, had a square connector rather then a circle.
Ripped the guts out of it and made my own plug and it works fine. It was just 1 wire that slips into the back of the brass piece.

Not sure if this helps, but mine is an N/A 2.2l and the box for the plug said it suited the 2.2l T aswell.

There are several threads on the the thermoswitch in the bottom of the radiator, including one I did.

The long and short of it, is that the switch at the bottom of the radiator has nothing to do with the operation of the fans.

The switch is open below 16degC and closed for temperatures above that. plus they were also only found on the GD1021 series cars on the GD1022, the system was changed. I am not sure what the switch really does, it signals to the ECU to do something, who knows what.

I am running a radiator without the threaded hole, and I have a GD 1021, I found that I could just use a joiner to join both wires together which simlulates the switch being over 16deg C (where I live thats most of the time) and its been fine.

The switch that controls the fans is in/near the thermostat housing and the connectors are different between manual and auto and different between GD 1021 and 1022.