radiator fan sending unit

[realetybytes]

Hello, my name is Ron. I am the owner of a 1978 Goldwing, which runs well. My problem is that someone has taken out the sending unit that controls the radiator cooling fan.
I have a new sending unit, but I need to know if it is a, "ground interrupt", switch, or if it has 12 volts running in and out of it?
I hope I explained correctly, and thanks in advance for the help!
Ron Reale

[WingAdmin]

It has one wire, and when the temperature gets high enough, the switch will close, connecting that wire to ground. The fan has two wires: one wire that is always hot, and the other that runs to the thermo switch.

[realetybytes]

Thanks, but the switch has two wires, actually metal posts on top, in the middle of some material that seems to isolate them from the screw-in body of the unit.
I appreciate the fan having two, lines, a hot and a ground, I just don't know which one this switch interrupts.
Thanks, and that's a pretty bike you got there, for one of those new-fangled types!
Ron

[N2PPN]

The two terminals on the switch are just that, an isolated, single pole, single throw, temperature controlled switch,which is Normally Open until it gets hot enough and then it closes, connecting up the fan's ground lead through the switch to chassis ground... an ohm meter and a hot pot of water will confirm this if you like... the terminals of the thermo switch are electrically isolated from the brass fitting that screws into the thermostat housing, eliminating any source of potential electrolysis in the antifreeze solution....

Hope this helps,


Rich

[realetybytes]

Helps very much. I miss living on Long Island, but not the cold or the prices!
Nice bike!
Thanks again, be well!

[Goldwing45]

but the question (on two wire) remains mystical... which wire is which, or does it not matter

[dingdong]

Doesn't matter. Either or.

[Goldwing45]

either or is cool.. I understand ty

[N2PPN]

The two wire switch is electrically isolated from the engine/bike's frame/ground. so there is no polarity to the switch... either terminal can be ground or fan lead..

Rich