Community Forums

prospector 1 · 07-20-2012, 04:12 PM

Hac anyone had any trouble with Sauer Don Foss fan system not circulating enough air to keep engine cool while driving down the road?
Ours will cool when idling with temp at 180-190 degrees after traveling a short distance the temps will go to dangerous levels and the alarms go off. New themostat and water pump installed and still having the problem. Freightliner called Guarantee in Junction City and they said to disconnect the two hydraulic lines to fan module and would make fan turn constantly. When doing any climbing or exertion, the engine starts to overhead. When you pull over, fan will cool motor!

Skip426 · 07-20-2012, 05:36 PM

This does sound just like the issue I had 18 months ago, rad fan control module not allowing the fan to go to high speed, when required.Don't see any year /engine info on your post.
The duty cycle for my hydraulic fan was 2 speeds , low/high depending on engine temp, fortunately it did not require any re-locating of lines to get the fan to go to high speed , when the module failed, only the disconnecting of power/ground wires from the flow control solinoid, was required to allow full fan RPM. Hard on fuel , but got me home without over heating.
Don't know the brand name of the pump and fan , but the control module was " Kypsor Medalion " and has 2 power supply circuits, both fused, 1 battery and 1 ignition. F/L was still able to supply the module and I found the defective part on the circuit board and am re-building my original for a spare.

Renipladlo · 07-21-2012, 02:22 AM

Hello Skip,
It would help a lot if you could provide the year and model of the coach.

The fan control is someplace near the fan itself on the frame rail drivers side of the coach and it a box about 2-4” square if yours is similar to mine. Sauer-Danfoss makes the fan control I think, however, do yourself a favor, and post your model and year info so owners of your year can chime in since they have had your problem and know what it took to fix.

FWIW-Lots of owners of SOB’s (some other brand of MH) look over the alpine forum who give advice or parts information, and they mean well with their advice because we are all one big RV'ing family. But recommendations from some other brands owners for parts in 99% of cases will not work on your coach for engine control systems for sure. So you need information from owners of your model and year, hence the reason why that information is important. Water heaters and furnace models are for instance installed across a wide variety of RV’s, so if someone has the same model water heater as you do, then the so and so for his would work in yours. Engine and transmission part numbers may not be the same, so you want information from alpine owners specific for your model/year coach for that stuff.

WRV used some very esoteric combinations of parts and specific ways in which they melded those parts for the application being engineered and so it would work the way they wanted it to work. General information for a Cummins engine might however be right on the money, since Cummins diesels for the most part operate in the same manner. The part numbers might however be different for fuel filters, for instance, as WRV may have gone with a different injection pump, and so that in and of itself would require different fuel filter numbers for instance.

Hope this helps, and if you’re new, welcome aboard.

EngineerMike · 07-21-2012, 09:58 PM

Actually WRV's solution for cooling was widely used in the Pacific NW. Both Country Coach & Monaco used the same Sauer Danfoss controller at some point, and prior to that used the Sauer wax valve control.

IIRC the control logic on both is to progressively shut down hydraulic flow thru a 1/4" control line; totally shut = fan on high. The electronic unit does it by the duty cycle relayed to the N.O. valve on the 1/4" line; the wax valve does it by expansion of the wax as radiator heats up (valve is installed in the upper rear of radiator tank) which shuts the valve manually.

For 2004 m.y. and prior Alpines, the radiator has the wax valve. 2005 m.y. to 2008 non-DPF engine has the electronic controller. In the 2008/9 m.y. DPF engines, there is a new control "Hydraulic Integrated Circuit" or HIC, with a 2 speed solenoid on the 1/4" line giving Hi speed, and Way the Hell Hi speed, and Sauer supplied some of the components but not the fan control valve.

prospector 1 · 07-22-2012, 02:54 PM

Regarding our last post, we have a 2006 Alpine Coach Limited with a 400 ISL Cummins motor. Thanks for the replies!

EngineerMike · 07-22-2012, 04:54 PM

Prospector- then your controller is the electronic unit, located on outside edge of frame maybe a little ahead of the fan motor. Looks like a square aluminum thing, has 5 wires, three connect to coach loom and two run from controller to valve mounted on controller. Part#1091170, FDCA NC 12VDC 1.2A HP3000, S/W Parameters: P0184204090A, comes w/a 7 digit serial# (e.g. 1200014) and a 4 digit # in upper right hand corner of label (e.g. 0431). Can be ordered through Berendsen Fluid Power near you (or not near you & freighted to you), & other sources.

You can run the fan on high by disconnecting the 12V power (red wire IIRC). If fan does not default to high when you disconnect the controller, there is a problem in the hydraulic drive components (pump or fan motor or lines, or (wild chance) the fan controller valve). At this point you need smarter diagnosis than me (probably before this point, but who's counting?).

daveshan · 07-22-2012, 05:35 PM

Mike, are the older wax valves still available? Inquiring minds of older coaches that get warm on long 8% grades on hot days want to know.

EngineerMike · 07-22-2012, 07:07 PM

Dave- yes, you can get replacement wax valves through Berendsen (see link in post# 6) and other dealers for Sauer.
One key on older coaches is an air conditioning cutoff valve. WRV didn't add that as standard, and since most early coach sales were in the Pacific N.W. that worked out. As folks migrated and had heating problems, one easy solution was to add an inline solenoid valve tied the the dash A/C control; when the driver called for dash air, the compressor kicked on and signaled the solenoid valve to close the 1/4" line to the wax valve. That kicked the fan on high for max cooling. Some coaches today that don't have the cutoff valve have issues w/dash air going overpressure (especially if running the dash air right out of the gate before the engine pushes temp and therefore fan speed up). I located a supplier for the valve WRV used, but haven't seen enough demand to fill a minimum order. If your rig is so equipped, you should check the valve to see its operating. If you don't have the valve, you may consider adding one.

daveshan · 07-23-2012, 07:45 AM

Thanks Mike, I was just wondering as the engine got up to 210º+ on a pull out of Durango to Silverton a bit ago in temps of 90ºF dragging the Cherokee.

I stopped at the top and looked at the fan and while turning it wasn't going very fast. I'll do some troubleshooting
Thanks
Dave

EngineerMike · 07-23-2012, 09:14 AM

Dave- 210 isn't my idea of overheating. Till you get another 10-15 degrees, I'd say you are in the optimal temp window.

prospector 1 · 07-31-2012, 09:33 PM

Well, we made it to Guaranty and unfortunately we need to replace the radiator and fan drive system. We want to thank you all for your suggestions!! Happy trails to you and see ya down the road!! A plus for us is that until the parts are in, we are going to the coast.

Renipladlo · 07-31-2012, 10:32 PM

I know the past VP of alpine has some of the new radiators in stock. I got the repair place in Phoenix to get one for my coach to fix it. Let me know if you want contact information. Sounds like the fan controller is bad, that is not so an expensive part I don't think but EM can provide that information which I need as well.

Keep us posted we are in Vancouver, WA and if you are heading this way, let me know so we can touch base, I can help you on the PC stuff.

Since I see you posted make and model, your fan controler is most likely just like the one I need to get for a spare. If I see the info I will pass it along. Make sure that Guarantee, puts the rubber support bushings on the bottom two support rods when doing the repair. If you need some info, I have some pictures I used for mine. Send me pm with your contact info, I will give you a call tomorrow and get e-mail address so I can send it along. You can also search "radiator problems" here and most likely find them that way as well.