Hello from Italy!!
So you're saying that the thermoswitch is a coiled thermal spring inside a housing that closes the circuit at a certain expansion?
This is the point of the light.
Which would follow if there is a spring instead of a thermal resistor.
I'm actually surprised that an auto manufacturer would use a coiled thermal spring for a temp switch. Even still, you never know what the aftermaket makes.
I like that idea, I hadn't considered that. But then again, what about the water pump driven fan? Either way, let's be realistic, take an old EA82 up a mountain in the middle of summer, there's a decent enough chance that it'll overheat during wheeling challenges. Such that I'm gonna want to put that fan on myself, and I don't feel like grabbing a jumper from my wiring box in the middle of the mess. Flipping a switch to an isolated circuit is just right.
This is an old car. The previous owner incorrectly wired the stereo, which subsequently was stolen and a lot of the wires were cut when that happened. Any circuit that fails gets a freshly rebuilt one and the important ones have 'just in case' backups. That's just how I am. That being said, I'd like my cooling circuit properly protected from power spikes that may happen.
Proper planning prevents piss poor performance.
By having properly built, protected circuits with indicators and redundant overrides, I will end up with an quick solution to faulty circuits in critical functions.
I'm not trying to say that my way of doing things is the only way to do it, if you want to do it another way, that's fine by me! That being said, if anybody wants to keep their engine from overheating and to have an indicator for their fan, this is the most reliable way to do it. It doesn't cost much, and it'll handle power surges, especially useful if you have winches and lights.