Just test for continuity, you don't need batteries or wiring...or anything.

 

I don't know why I over complicated that....I like to do that sometimes. It's like testing any other switch or safety.

 

You guys are making this way to much like work.


Here is a suggestion Jeff.

When the relay turns the fan on (high or low), verify that the thermoswitch is closed .

When the fan turns off after a couple of minutes, verify that the thermoswitch is open.

This will confirm that the fan is being controlled by the thermoswitch and the relay.

I think the fan and control is working correctly. since your temps is set relatively high, it only takes a couple of minutes/seconds to cool the coolant and open the thermoswitch. Set that switch at a lower temp and it won't turn off so quickly, and might even stay on after the coolant thermostat is closing.

Remember-the oem thermostat is not even completely open until 203*.