I have a 3 gauge deal hooked up. Ammeter, oil press, and water temp. My water temp gauge previously operated excellently, letting me know when i had to turn the fans on nicely... after i have replaced the thermostat to a 195 one, for the winter time... i cannot get my gauge to read anything! says its never hotter than 100 degrees but im sure the motor is heating up adequately because i get heat inside and you can just kind of tell. i removed the gauge entirely and checked the small wire which runs in the middle and found it to be intact and with no cracks or breaks. The coil-wire around it does seem to have some damage, is it possible this would cause the problem. I always thought the temp was controlled by the middle, inside of the coil, wire. Remind you, I am talking about an aftermarket mechanical-like gauge, mounting in the intake manifold. Also, i have checked cooling system to make sure capacities are correct. Water pump operation is good, thermostat opens, but the gauge never reads temp!

those gauges are cheap enough you could just buy a new one and see if it works.

anybody else have a guess at it? i don't see why the gauge itself would fail....thats all

Senders can go bad...gauge can go bad.

Like said they are cheap enough to just replace. Can't imagine it'd cost you more then $30.

Coil wire? What does that have to do with the cooling system?

Around the thick wire which carrys the actual temperature for the gauge to read is a coil-like wire. It is not the coil wire.

It looks like a very long, stiffer e spring-like coil wire. It is broke in a few places and my main questioning was on whether i was right in assuming that only the inner portion of the wire was what carried the temperature to the gauge, and why it would stop functioning out of no where.

I go through one of those sunpro water temp gauges every year and a half to 2 years. They're cheap, and you get what you pay for.

I currently have one in my cowl. And I know what you mean about the thick wire and coil spring. At the end there is a little pill-like capsule which I guess has some sort of filling that travels up the thick wire into the gauge... Maybe the sending capsule broke... but agree in replacing it. I got mine for $10 at Advance Auto...I think they were on sale...

so pretty much, if it is just like hanging at the bottom not doing anything...you have to replace it? lol, cause that is what mine is doing... xD

pretty much... they're considered disposable...