Radiator Fan Runs Continually

[tjshively]

2005 Alpine Coach FDDS, 2003 Saturn LW200 Toad

I have been reading about this wax valve.
The radiator fan on my coach runs continually and the water temperature runs around 178 deg. at 65 mph. It goes up to 190 at 75 mph.
Do I have a problem with this wax valve? What is it? Where is it? How do I check it?

[wolfe10]

Does the fan always run on HIGH. The fan is not ON/OFF, it is low speed, high speed, as you need air flow over the CAC (Charge Air Cooler-- aka Inter-cooler, aka After-cooler) to keep intake manifold temperatures where they should be.

And, fan speed should not really be related to coolant temperature except under heavy load conditions.

Said another way, the thermostat is what sends coolant to the radiator (or not). Sure, lots of air flow will cool coolant returning to the engine from the radiator just as will use of the dash heater, but that just means the thermostat sends less coolant to the radiator.

If you get a chance, pull into a rest area on a cool day, flat or descending grade. Leave the engine running-- use cruise to set to fast idle. Best to use a strobe tach to check fan speed OR "feel the air flow"/listen to air flow.

Do the same after a long hard upgrade, particularly at high ambient temperatures.

Any difference in fan speed?

Do the same after a long

[Old Scout]

Do a "search" on this forum--there is a night's worth of reading on this subject. First, manual wax valves were not used on Alpines after 2003 or 04--so your coach has an electronic fan controller. Second, lots of discussion/debate about how fast the fan runs at idle but it is generally viewed that the fan will turn at some number of RPMs, even when the engine is not calling for cool [PS--unlike the wax valve, your electronic controller also ties the dash A/C systems needs for cooling to engine fan speed]. "Assuming" your engine fan is running at high speed continuously, there is probably something wrong with your electronic fan controller. Need to confirm the fan is actually running at high speed, then get the controller checked......