Fan swithch wiring

[katsi]

For those of you who recognize the name, I still have not been able to retrive anything from my cylinder so, I'm moving away from that for a while and will continue to try different methods from time to time. Anyway, I just put in a new fan switch on the new radiator and worked through the wiring diagram to find the "ORIGINAL" wires to hook everything back up to stock. And, as ushual; I have a couple of questions.

1979 Spider
1) from the fan switch their are two leads that go to a plug of some sort that is supposed to plug into another plug to compleet the circuit. Unfortunatly, my receptor plug has been cut off and discarded sometime it the past. So, I was wondering which end is negative and which end is positive? Actually, I think that the fan switch is simply something that closes and compleets a ground contact to allow a current to flow through the fan motor (correct or not). Therefor, it doesn't matter which one I connect to the fan and which one I connect to the ground? Yeah, that was a question.

2) Again concerning the fan switch, is it a good idea to connect a second switch that would bypass the radiator fan switch so that one could turn on the fan manually during traffic on paticularly hot days? And if so, would you do it by simply running a wire from the fan ground to a switch located somewhere in the driver's compartment and then back to a ground to bypass the radiator fan switch? I hope that makes sence.

[seabeelt]

Katsi, Not sure if the 79 is the same as a 78, but the light blue wire comes from the fuse box and goes directly to the fan. The black wire from the fan then goes to the thermal switch and the other black wire from the thermal switch goes to ground. In the case of the switch it should not matter which side you ground and which side goes to the fan.

Most folks install the bypass switch due to either wiring problems or cooling problems (mostly due to air in the system) to better control the fan. If everything is functioning as it should then you do not need the bypass switch.

[katsi]

Seabelt - yes, it's exactly the same - light blue is power to the fan motor and then goes to the ground via the fan switch. Just didn't know if that fan switch needed to be hooked up in a way that current only flows one way - does that make sence?

[kilrwail]

The fan switch would work either way. You shouldn't need a bypass switch once everything's working properly.

[So Cal Mark]

I feel the main reason for an additional switch is as an emergency backup to overcome a failure in the system