85 Maxim-X Thermo Switch

I pulled out my thermostat housing and I noticed no wires are attached to my Thermo Switch that goes to the fan. Instead it seems they are attached to an actual switch under the gas tank. This actual switch does look proprietary but I cannot find it in my manual. Any suggestions?

 

Seems to me like a previous owner added a switch to turn the fan on and off instead of leaving it up to the thermostatic valve (not a bad idea in my opinion).

 

I know this is a dumb question but.....How do you know when to turn it on?

 

When the engine gets hot :lol:

Someone had to say it!

The thermal switch will normally trip when the needle is almost up to the red zone. Intuitively, that seems to be too late, but it's actually only 195 degrees. We don't know that since the temp gauge doesn't have any degree markings.
The best way to have it wired is with the manual switch in "parallel" to the the automatic switch. That way if you aren't paying attention the auto switch (if working) will turn the fan on when it needs it. BUT, you have the option to turn the fan on early when you know you'll be sitting in traffic so you can keep the whole thing cooler from the start.
As long as the PO used the original wires, the fan SHOULD be protected by the fuse and will turn off when you turn the key off.

Some owners have ran a seperate power wire from the battery to the switch then to the fan and if you forget to turn it off the fan will continue to spin with the key off and drain your battery quickly.