HELP!!!

[Jackduncan]

I just purchased a 2004 Alpine and the a/c unit needded to be repaired, after completing the repairs cummins found that the Hydraulic value that runs the cooling fan in not working do any one know where i may find a new value.

[Old Scout]

Are you talking about the mechanical [new model could be electronic] wax control valve on the radiator or the controls on the fan motor itself? Becareful about accepting the diagnosis that the "valve" is "not working" at face value. If the "valve" was stuck open, your engine would quickly over-heat. If it was stuck shut, your engine would run very cool [below 170 degrees]. I know it sounds reversed but a closed valve activates the fan while an open valve shuts it off. Do either of these engine temp conditions appear to true?

PS--the wax valve alone is more than $300 installed--I am sure they would love to replace it for you.

PSS--if they dont know where to find a replacement valve part, they probably arent qualified to diagnose it.

[Jackduncan]

Cummins is saying it is the hydrauic value that controls the engine cooling fan and their is no numbers in this part so they don't know where to get the new value. I can not understand why this would not be a common part on all cummins engine that have AC. Did Western Alpine have one made just for their coachs?

[Sammie]

Jack, Try reading this thread. It may have information you can use.

Sammie

Cooling Fan and air conditioning switch

[EngineerMike]

My impression (from reading one or two iRV2 threads over the years) is that the 04 models mostly have the wax valve setup, while the 05 units have an electronically controlled valve run thru a Saur Danfoss fan controller. Could be some earlier coaches have the SDFC. The fan controller, if you have it, was usually mounted on the DS of the DS frame C-channel, just ahead of the radiator fan hub.

[Old Scout]

This is not about Cummins engines with A/Cs, its about MHs with side-mounted radiators/hydraulic fan motors [probably something yr Cummins' guys dont see much of unless they do a lot of RV work]. Determine if its wax or electronic valve, then seek out a major RV repair facility to find the part.

[Jackduncan]

We took the wax value off first and took it to a hydraulic shop to test the operations of the flow and we were told that the value was working fine. The next was to take the fan motor and have it tested along with the wax value remounted and it also word good. AT this point the only thing left is the control solenoid back to the hydraulic shop to test it to see if it opened and closed and it also worked. The only question is it is controlled be heat and we done know what temp. is it opening or closing.

Cummins is putting it all back together and going to re-test the system will let you know if it works.

PS sometime the cummins dealers done know the systems on the motorhomes as well as this group.

Thank you to all our freind who help us understand how the system works.

[Old Scout]

Still have to ask--so what were/are the symptoms that causes your Cummins folks to arrive at the original diagnosis that the "valve" wasnt working?

[Jackduncan]

They said that the fan was not coming on when the AC was running, I think they did not know when it was to come on and turn off so I think now that they understand that the systen is working the way it should be.

[Jim Bragg]

Jack I run the Silverleaf VMS on my 2003 ISL 400. The thermostat opens at 182 degrees then the temp will cool off to 178 degrees, then the temp has to go back up to 184 degrees before the wax valve opens or closes and the fan starts. I can see the fan start when my manifold temp starts to drop. Not a perfect system per Mike Young at Cummins Northwest.

[rmmpe]

In my opinion, the cooling fan does not have to automatically start with the AC (mine didn't). If the system senses temperature properly and responds accordingly, you most probably don't really have a problem.

Do you have a Silverleaf? If not, you may want to strongly consider getting one. Again, in my opinion, they work very well and are perhaps the best method of knowing what your Coach is doing on the fly. The VMspc is wonderful.

I don't have the Alpine anymore and I sure miss that VMspc.