i have a fiesta top thermostat housing with the connecting plugs for a fan, but when i took it out of the fiesta there was a third cable i had to disconnect from the bottom part of the thermostat. and now i notice there isnt one of these connectors in the sierra, so will it work? what is that third cable for?
Rescued attachment thermostat.jpg

What is next to the fan switch..

Looks like a temp sender for the gauge...

My fan switch looks more modern with a connector arrangement and next to it is a pipe connection for the expansion tank.

[Edited on 14/6/06 by SeaBass]

rip the black tape from the wires, you will only need the two to the fan switch the other can be disgarded ( personally I would bin all the wires and make new ones with a new fan switch)

ATB

Mark

ok... thats one of the possibilities that i thought. but how exactly can it work if under these two main connectors there is only a metal plate? how does this thermostat send the signal to the fan?

i think the third connector is there to give a comparison of a temperatire and then the fan kicks in....

anyways... i'm thinking of just plugging it in, of course with new wiring as the cables are completely crimped, but i guess it wont work...

One metal plate???

Ok two wires, there is a switch in the body that detects the temperature of the water, when it get to the required temp the switch makes and sends a current through the switch and to the fan.

They aren't rocket science so don't look too deep in to it

ATB

Mark

see. i'm being a bit thick about this but thats it. the third cable goes to the temp switch.
wait....
edit: wot? "makes a current"? the problem i have is understanding where does the fan get its energy from? i presume its from the alternator.

[Edited on 16/6/06 by robertst]

depends how you want to do it, some people use relays some don't,

If you don't use a relay you would have a permanent live from the fuse box, to the temp switch, then from the temp switch to the fan, the fan to earth. So when the temperature increases the temp switch will go from open circuit to closed circuit and send the power from the fuse box to the fan.

I'm crap at explaining things so someone else can explain the relay circuit

Sorry

ATB

Mark

It's not much different, except the temp switch triggers the relay. This then switches the fan on/off.