Engine Cooling Fan

[Mike Shumack]

The engine radiator fan is hydraulically operated and controlled by the "wax valve"

On my C-12 from stone cold, it takes 20 minutes at 1000 rpm fast idle to get the fan to engage.

Just to add - on my C13, the fan runs (although turning slowly) with a cold engine at startup.

[David T. Richelderfer]

Mike - I have not been under the C12 in our coach.  Thus I have not looked for the auxiliary transmission cooler.  But I think it is located first inline from the door - streetside aft door behind the tag axle.  It appears to be about the same length and 2/3rds the height of the engine cooling radiator.  I took three pictures and the message above says the "attachments are now attached to this post."  I guess we'll see if they are.  They might need a good cleaning, eh?

[David T. Richelderfer]

Our engine compartment cooling fans.  I have heard and seen them running a couple of times in our seven years of ownership of the coach.  The rear engine door opens only to horizontal, so this picture is looking straight up.

[Steve Huber]

The engine compartment cooling fans are most likely controlled by a "snap disk thermostat". If you want them to run longer, replace the thermostat with a lower temp unit. Be sure it's wired to a constant 12v source as you want the fans to run after the engine is shut down to cool the compartment.
 https://www.google.com/search?client=firefox-b-1-d&sxsrf=ACYBGNR0vHpr3dSJdvMhqGt5qtV14AXF3g:1570326438581&q=snap+disk+thermostat&spell=1&sa=X&ved=0ahUKEwiO97XswYblAhXNi54KHcKiBX0QBQgtKAA&biw=1280&bih=556
Steve

[Jerry Emert]

Yes mine is the dual fan system on the cover.  It is wired through a 5 amp fuse to the sense wire on the back of the alternator.  I found it when my alternator went bad.  The old fuse had melted and I thought (hoped) that had been what caused the alternator voltage to be 10 volts instead of the required 13.8 or so.  No such luck!  Alternator was also bad.

[Gerald Farris]

Most of the auxiliary engine compartment cooling fans are powered by a module that turns the fans on when the ignition switch is turned on, and continues to power the fans for 30 minutes after the ignition switch is turned off to cool the engine compartment as the hot engine cools down. This system is designed to prevent excess engine heat from heating the bed that was located directly above the engine in earlier model coaches. This system was phased out as bedroom slides that moved the bed away from the engine heat became more common.

Gerald

[Jerry Emert]

I got under the coach today.  Here is wher the transmission lines go to.  It is vertically mounted rectangular box mounted to the right (fwd) of the radiator.  The large pipe is going towards the front of the engine and is either the water that goes into or comes from the radiator.  Not really sure of the flow.  Still trying to figure out where the water pump is.  I think I found it and a coolant leak on the rubber connection between the engine (water pump maybe) and that large coolant pipe that is attached to the bottom right (fwd) side of the radiator.  My set up looks pretty much like the pics David posted above.  I found the CAC, radiator and oil cooler on bottom of that stack I think!  Making progress!  Pics are looking up at it.  2nd pic has large pipe that goes to the front of engine.