Coleman 2022 UT 400 radiator thermo switch replacement question

[moonrover]

Mine is overheated/burned/melt at connection with its wire connector, parts are ordered to replace both them.  This seems to be a common issue, and some of you already replaced it. I right now just connect the wires, so the fan runs  all the time whenever the initiation is on, but it's better let fan runs as needed with a working temperature sensor/switch. 

Question: Does some coolant come out by removing the switch/sensor from radiator?  Or, is the threaded hole all the way inside radiator?   If the answer is yes,  I want to drain or extract  some coolant to make its level below the sensor before replacing it, so I don't make a mess with coolant spilled out 

Thank you.  

[aefron88]

Normally yes it touches coolant and you'll need to drain below that level and refill after replacement.

When you refill the radiator, these things can be a bear to bleed all the air from the cooling system. Any air left will lead to more overheating issues. There's a plug on the right side of the engine where the rad hose goes in that you can partially loosen while running to help bleed air.

[moonrover]

Thank you, aefron88.

My ordered  switch came today, and I installed it. Before I installed it, I extracted the coolant through top radiator with the pipe reach its bottom. Only about 200 cc came out, so when I removed old switch, almost no coolant came out from there. After I installed the new one, I poured back the extracted coolant through top of radiator. 

I'll test runs to see if fan runs when engine/coolant  is hot enough ( I believe at least 75 C), and also if overheat happens due to air in the system and requires bleeding.

[moonrover]

Test drive today. The new switch works as it should. Fan runs after engine runs a while and is warm up.

[aefron88]

Congrats. You're not the first report on here of a broken fan switch. Glad you got it all sorted

[Joe Breaux]

I replaced mine with an adjustable switch.We tested oem and it did not engage fan   til over 230 degrees F. This is why it blew headgaskets and the heat in the cab was unbearable.Set new switch to come on at 180 *F. Cab is much cooler and no more boil overs.