Possible Electronic Hydraulic Fan Controller Problem

[LSBEH]

Hello guys,
I think I have the same fan controller issue that you all have had (engine fans roars, fuel mileage down, engine runs cooler than usual even on grades, etc). I'm wondering if any of you can give me some updates...so I'll format with questions....
1) is the manufacturer still in business in Ames, IA ?
2) can you purchase direct from them ?
3) do they rebuild these FDCA units ?
4) do they have an exchange program ?
5) if I take the unit apart myself can I get interior parts or a rebuild kit from them (such as o-rings) ?
Any other suggestions or ideas is very much appreciated !!
My unit is an 05 Dynasty and we really enjoy it
Thanks
LSBEH. (Harvey)

[dawgdad91]

I also have a similar issue with my 2006 ITASCA Horizon, ISL 400HP. It is on a FCCC. Uses the Sauer Danfoss Hydraulic cooling fan

Usually runs around 179-183 going down the highway at 60 pulling a VW.(any air temp). Thermostat works.

Hot going over Rockies from East on I 90 last Summer, 220 until I got it down into 2nd and ran it at 1700. (93 air temp). Cooled right off after I stopped on top for a while. Back to 179-183 rest of trip.

Hot again last week climbing Stevens Pass eastbound on US 2 in Washington
state Again 220 until I got it into 2nd gear. Stopped on top. This time it stayed between 199 and 208 even when I started down of pass. (98 air temp).

Thermostat works fine. opens around 180.
*Fan always runs*. speed dictated by engine RPM.
Constant dust cloud on dirt. A/C on or off, fan runs the same speed.

I removed the Charge Air Cooler and Radiator today, second time in 3 years.
Both full of dirt and sand.
Unfortunately, Small rocks got in side the fan shroud between fan and radiator and caused considerable damage to the radiator. It is salvageable but just barely.

So, I believe my overheating was due to dirt and sand in radiator. We shall see when I get it put back together and I make a run up to the ski lodge towing the VW.

Last but not least, I think my Danfoss fan controller is not working properly or at all. I am hoping to get some information on the hand made switch built by TWOMED I hope I got that correct.

I only travel very short distances on the dirt, but even that is evidently to much. I would love to be able to turn the fan off completely for short distances, or at least get it to run very slow.

Thank you for any assistance

[EngineerMike]

It would be great to have a work around for the Sauer-Danfoss controller. When they were a current part and made by the hundreds, they were about $300 retail and used by Monaco, Country Coach, WRV and possibly others, and came in 3-wire and 5-wire versions w/programming as specified by vehicle mfgr. Not that they are a one-off setup, they can still be had but its about $700 at last count and couple of months lead time.


For 05-08 non-ulsd models WRV used the Pulse Width Modulated signal available as an option from the Cummins engine based on engine temp, so the fan speed was scaled based on relative temp, probably the most efficient setup vs step-wise rpm ramping. 04 & earlier had the wax valve, and 08+ ULSD engines have a two-step system Cummins driven w/a single trigger point that sets RPM of fan to HIGH!!!! (up from HIGH! for minimum engine temp)

[dawgdad91]

TwoMed,

Thank you for all the info. Still working on it and will let you know how it works when I get it all figured out.

You should see the F model Chinook. All glass cockpit. A thing of beauty, until something goes wrong.

Thanks again,

Scott

[Marca]

I never thought I would have to return to this post 7 years later, but here I am. I took the Apex to a shop that specializes in radiator and air conditioning repairs to get my dash air repaired as it was no longer cooling. In fact this shop did my new radiator last December. Took three weeks to get it done as had to send the old one to an Alabama truck radiator shop and have the new one built. Also, had to get a new CAC. I am told this radiator is better built and has the vibration dampers installed correctly. Anway, they did a great job just took a while.

Regarding the dash air repair, the Service Manager checked out everything he could and says he thinks the ECM is not sending a signal on engine start up to start the fan so when the engine is cool below 185 or idling in traffic and not up to 185 or not going down the road there is not enough air flow to keep the AC line temperature down and the high pressure side goes too high. We proved the electronic hydraulic fan control contraption is kicking on and off at about 185 degrees. My workaround is to keep the air conditioner off until I am going down the road or the engine temperature is in excess of 185 degrees. That way there is enough air flow to keep the a/c unit cool with or without the hydraulic fan controller contraption. He verified that the engine radiator thermostat was opening and closing properly. The workaround is until I can get it into Cummins which I hope to do shortly.

Does this potential ECM issue make any sense to you or do I need to pursue a different direction? I assume Cummins is the one who has to do this. I really hate for them to have to touch the VANSCO or any other non-Cummins system as other problems seem to be born. Sorry for my laywoman’s use of the technical term “contraption”. Without IRV2 and your help and others, I would have stopped a long time ago and not had all this fun. Chuck's famous last words of advice to me were, “Don’t take things not working correctly so personal. Equipment breaks down, you get it repaired and go on.” Easy for him to say……Thanks, everyone.

[EngineerMike]

Marca-
Vansco is uninvolved so long as the AC clutch is activating, no reason to discuss it further w/them.
The Cummins ECU has a 50 pin "OEM" plug that WRV supplied. In this plug Pin# 29 is a brown #18 wire labelled EFAN-RTN and is the ground for the fan controller, Pin# 38 is a white #18 wire labelled EFAN-PWM which is the fan speed signal. The ECM is supposed to be set (Cummins calls it a "parameter") to issue a pulse-width modulated signal on #38 that produces ~800rpm fan speed at cold idle, and proportionally higher with engine temp rising. AC call should also kick this PWM signal up to high to avoid the high pressure override you are experiencing.


The AC input originates off the dash control, Ground signal goes to front VMM which a) sends multiplexed signal on the J1939 CAN buss (twisted wires running front of rig to rear), which signal is picked up by the rear VMM which connects +12V out to the AC Clutch, and b) (which I believe but cannot prove) the ECU should also pick up said J1939 signal and default fan speed PWM signal to high. I don't see any other input to the ECU that would account for the input, therefore my conclusion the ECU (which reads all sorts of other J1939 signals) should respond accordingly.


I can send you facility, or you, photos of the wire loom elements that show these circuits. Shoot me an email if needed: engineermikef @ gmail.com

[Marca]

Thanks, Engineer Mike. I will be taking the motorhome to Cummins Coach Care in Elkhart sometime this month and will give them this info. I am sure they will be in touch if they need more help. Have a great day!