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Erratic Fan Controller

Yahoo Message Number: 64514
I've read many posts in the archive on Sauer Danfoss Fan Controllers, but found nothing exactly like my situations. I first experienced erratic high engine coolant temperatures last spring. I had John Davis (LaPine) analyze and he found a bad coolant input sensor. He replaced both coolant & air sensors. Engine temperature was "normal" (192 >197 & occasional up to 205) for the next 1,500 miles. Then periodically I began experiencing High (218-223) engine temperatures. Took Coach to Cummins-NW Corburg. They found nothing wrong with the fan controller & they surmised the coolant thermostat was functioning properly. With apparently no option other than throwing big bucks at a suspected bad controller, I headed to the Midwest on a 4,200 mile round trip. Only had an occasional erratic high temp situation for the next 2,900 miles. Which were resolved by turning on the A/C switch, slowing down and waiting for the High Speed Fan Roar to drop temp. Then yesterday in Wyoming the high temps would not stop. So, I disconnected the 2 prong connector which puts the fan in default Hi-Speed, that keeps the coolant temp between 178 to 181. Not optimum, but better than overheating. All High temp situations have occurred with outside ambient temperatures less than 70 deg. Not always climbing a grade. And the occurrences seem to happen after driving several hours, then stopping for a ½ hour and then the erratic behavior happens when we continue. Guess it is time to buy a #1090409 controller from Berendsen Fluid Power in Atlanta. I found George's operation explanation of the controller interesting & appreciate Don Scheluse's much information on the Problem. Is there any validity to heat for the nearby muffler effecting the controller's operation. Why would CC Engineers place an electrical device so close to a High Heat source?? Let's see how today's 500 mile drive from Rock Springs, WY to Caldwell, ID goes with the 2 prong connector connected.
LeeCasebeer x '01 Intrigue #11219 with 106K miles

Re: [Norton AntiSpam][Country-Coach-Owners] Erratic Fan Controller

Reply #1 –
Yahoo Message Number: 64518
Since you have had competent techs try to analyze your heating issues, I doubt I can help much. But, the first thing I would think of is a faulty/sticky thermostat. On gas vehicles thermostats are cheap, don't know on diesels. And getting to them may be a major chore.
Trying to help.

Jack Nichols, 2003 Intrigue 11527

Re: Erratic Fan Controller

Reply #2 –
Yahoo Message Number: 64524
Lee, I long thought that the failure mode of the controller was always to run the fan on high at all times. You and others on this board have pointed out the error of that thought. I think you also make a good point about the proximity of the muffler thought there is a fair distance between my muffler and the controller. There is open air flow between those elements also. The controller will experience3 some heat gain just from the hydraulic fluid that runs through the variable valve side of the device.
Others on the board have installed a switch to control the power supplied to the controller. I know Don Seager has don that on his 2004 Allure.
I think you are right that you are about to estqablish a relationship with Berendsen. Good luck.

George in Birmingham
'04Allure 31038
George in Birmingham
2003 Magna 6298

Re: [Norton AntiSpam][Country-Coach-Owners] Erratic Fan Controller

Reply #3 –
Yahoo Message Number: 64539
Lee,

I agree with Jack as well. We had a similar situation happen to our '06 Inspire and it was suggested we change both thermostats. When they did they found one was broken. The issue has not happened again since they were both replaced. Ours was 3 1/2 years old and they should be changed every 3 years. It's not a very expensive fix to do either. We do have a 400 cat but I would assume the cummins is close in requirements. Let us know what you find.
Safe Travels,
Kathy

'06 Inspire #51782

Re: [Norton AntiSpam][Country-Coach-Owners] Erratic Fan Controller

Reply #4 –
Yahoo Message Number: 64540
So far it seems that a bad thermostat was our problem as well. I had it changed this fall and some very erratic temperature swings went away traveling in some very hot weather. Low temperatures almost always point to a thermostat. Overheating on the other hand can be many things including a bad thermostat.
A lot of Cat engines have two thermostats and somewhat difficult to get to but few Cummins have two. My 370 ISL only has one and it is right up on the front of the engine and fairly easy to change.
Before I got into controller and sensor replacement I would make sure that the thermostat/s are ok.

Don Seager

2004 Allure 31046

Re: Erratic Fan Controller

Reply #5 –
Yahoo Message Number: 64570
To all: Early this year, at the beginning of 2k mile trip, my fan coolant sensor on my C-12 CAT went bad, locking fan on high. Once I replaced it with one I purchased from Colton, the problem was solved, however, my engine runs a little hotter now, never overheating but cycling between 194 and about 205 (with A/C off--it drops to 188 with A/C on) sometimes up to 210. I spoke with Colton and they said that this higher temp range is actually optimal.
Whether this is true or not I cannot say, but I should point out that assuming all else is OK, the operation of the fan is simply a function of the resistance curves of the coolant and air temp sensors in these non ECM controlled fans. I am wondering if the resistance curves of the new coolant sensors they are selling us these days are a little different than the orignal ones (mine was 8 years old and the new one seemed to be a different brand). This would explain everything. Someone with an Ohm meter and both a properly operating new and old sensor could determine this pretty easily.

Rich 2002 Magna

Re: Erratic Fan Controller

Reply #6 –
Yahoo Message Number: 64575
Lee, I like to add my two cents worth and say that with the age of your coach and milage and as long as you're spending the money for the new Sauer Danfoss Controller that you also change the engine Thermostat.

Thanks, Mike 03 Allure 1st Ave #30898

Fan controller

Reply #7 –
Yahoo Message Number: 64515
Lee,

Interesting post. I have exactly the same situation. On our last trip my temps went up to 230, twice. Moderate OAT and running on the flats. I had recently found that the two prong plug you refer to (12VDC input to controller) had been disconnected for maybe years. Thus my mpg was always about 7.4. When I connected the 12 VDC things began operating properly; temps went from low 180's to 198-205. MPG went up to 8.5. That worked for about 2000 mi and then things went south. Sometimes very low temps and sometimes extremely high. I have spent several days testing the system but am frankly stumped.
Lyle Wetherholt
04 Intrigue 11740

Re: Fan controller

Reply #8 –
Yahoo Message Number: 64520
Lee,

I am not sure if this will help, but I had a switch installed that in addition to the fan coming on automatically. I can turn on the fan in anticipation of a steep hill or in slow moving traffic.

Stan Inspire 2005 51406

Re: Fan controller

Reply #9 –
Yahoo Message Number: 64521

I'm having the exact same situation. My fan controller was replaced in 2007 and everything ran normally until last summer. Then, after running for several hours, the temperatures would slowly increase and eventually the Country Coach (not engine) warning light would come on with indicated temperatures of about 230 degrees. I'd slow down (from 55!) or increase engine rpm and the temperature would decrease. All this on fairly flat freeways with ambient temperatures in the 70's. I finally resorted to pulling the fan controller fuse to force the fan to high speed. I went to Colton truck and just recently to Cummings Northwest but no one can find anything wrong. The radiator is clean and I had the cooling system drained and flushed. Supposedly they even have checked the sensors and found them OK. I had Kevin Waite of Junction City, Oregon install a switch to allow disconnecting the fan controller circuit from inside the coach (Kevin did a great job!!). Cummings Northwest even installed heat shielding around the temperature sensors - with no change in behavior.
I'm hesitant to continue to run the coach with a high temperature indication and with the warning light on until the engine overheat light comes on, but that's likely the only thing which would show whether it is a sensor error or a real overheat! I believe it is a real overheat since pulling the fan fuse thereby forcing the fan to high speed lowers the indicated temperature on the gauge. Perhaps someone with a Silverleaf monitoring system has had a similar problem?
The really odd part is that it runs just fine for several hours which shows the sensors and fan controller are operating OK at least for a while. Then the temperature slowly increases until the light comes on..... It's as though the fan controller (at some point) does not force the fan to high speed when needed, but keeps the fan at a lower speed - too low to prevent overheating? I'm at a loss on how to find the problem and also hate to just replace the controller if it tests OK.
We recently met a couple in Eugene who reported having this same problem on their 2000 Allure. They said they had it fixed, but at that moment couldn't remember what was done to fix it - but it was fixed! They were leaving the next day and it started to rain so we were not able to follow up....

Charlie

02 Allure, 30763

Re: Fan controller

Reply #10 –
Yahoo Message Number: 64522
Lyle, your current situation probably explains why a previous owner unplugged the power supply to the fan controller. I have little doubt that you have either a sensor or controller intermittent failure. My vote is that the controller has failed.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Fan controller

Reply #11 –
Yahoo Message Number: 64526
Charlie, your intermittent problem would be real tough to diagnose with certainty. The last time mine failed it wen through a period of intermittent failure before a final hard failure to high speed.
With the experience of two controller failures. And with a Silverleaf that allows the user(me) to closely monitor data. I am convinced that you have controller failure. The good thin is that in a world where many motorhome fixes start in the thousands this one starts in the hundreds.

Good luck.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Fan controller

Reply #12 –
Yahoo Message Number: 64527

All

the one issue that I haven't seen disussed i.e. overheating is fan speed be sure to check that the fan is running at approx 3000 rpm at max throttle.
Jim
31535

07 Allure 470

Re: Fan controller

Reply #13 –
Yahoo Message Number: 64541
My coach overheated a couple of times and both times the fan was not running on high. I rigged a switch to disconnect power to the controller, forcing it to high. Having this switch, I've become convinced that the controller malfunctions but, is reset and returns to normal by cycling the power with my switch. Anytime the temp get over 206 or so for any period of time, I reset the controller and the temp goes back down and then works normally. A new controller might fix it but, my fix only cost a couple of bucks and took a couple of hours.

Greg Jones

'03 Intrigue 11571

PS - I'm at Cherry Hill and there are 6 or 7 other CC's. Save for a couple of Vantare's, the class of the place

Re: Fan controller

Reply #14 –
Yahoo Message Number: 64542
Its easy to check if you are having a real overheating problem. Pull over & hit the return pipe (radiator to engine) then the radiator feed pipe (engine to rad) w/an IR temp probe. Coolant coming out of the engine should read the same w/in maybe 3 degrees as your reported engine temp (sensor), and you should be maybe 160 on the return to the engine.

I'm betting these are sensor issues. Mike

Re: Fan controller

Reply #15 –
Yahoo Message Number: 64545
Hi Friends, Just my two cents. Having an older Allure that is much simpler then your newer CC's Reading your posts its a shame CC used the System on newer coachs to control the cooling Fan. Our old Allure uses the Wax Hyd. controller spool valve as I would of called working on Cat Diesel Power Systems. Cat years ago used Robertshaw Wax sensors and very reliable. Too late for me but Years ago me and our Eng. group would of came up with a better Cooling Fan Controller in Place for you enduser's. Remember our Power Systems run Hospitals, Radio and Tv back up power and some prime electric supply in remote locations. Its a Shame you on newer Coachs Pay Mega Bucks for your rigs and have Cooling Issues like your having. On our Larger Cat 2 Megawatt Power Modules we used a 200 HP. three Phase motor to belt drive a Fan for Charge Air Cooling, Diesel Fuel cooling, Oil and Coolant. The Fan Motor ran as long as the Engine is running. The Fact is Cat like CC Had systems that worked and often faild. Im sure if Bob Lee was In Place he would have a currant fix. Cat made thousands of Power Modules world wids as CC only made thousands of Motorhomes. As a field Tech. it was my Job to insure proper Engine installs for the Cat Warranty to take effect This system would of sent a flag to me and would of taken CC'S Fan controller to Eng. office and have a meeting with CC Rep. also. My job was at stake! Like me there CC Owners retired form the Power Biz. and yes some are Owners. On our Old Allure with 75k miles the Wax valve is still going on strong. Im off my Box now. Best of luck on outcomes and enjoy yhis group.

Ken 99 Allure 30356

Re: Fan controller

Reply #16 –
Yahoo Message Number: 64551
Stan

I had the switch installed until I was able to obtain the new controller. When the CAT dealer installed the new controller he said he could not leave the switch hooked up. The wires and switch are still in place but not connected .

Dan 2006 Allure 31348

Re: Fan controller

Reply #17 –
Yahoo Message Number: 64552
Dan

I do not know why they could not leave the two systems hooked up. I have had my current system for about two years, and I think it gives me a little advantage to anticipate steep hill or knowing I am going to be in traffic.

Stan Inspire 2005

Re: Fan controller

Reply #18 –
Yahoo Message Number: 64562
I also experienced this same scenerio. First year I had the coach, no problem. Second year, on a steep grade in Colorado, going to Breckenridge, CO from California, it overheated on the grade. I experienced three cases of overheat, which was documented by Catepillar through the on-board computer. I replaced the radiator; cooling tower, and ECM, and still overheated on steep grades. The fix; disconnected the ECM and left the fan on high all the time. Not the best solution but plan to install the "switch" in the cab so I can do the disconnect when necessary.

Bryan

2006 Inspire

Route Through Boston

Reply #19 –
Yahoo Message Number: 64613
We're heading down tomorrow from Maine to a RV park that is apparently 3/4 hour south west of Boston, this area is unfamiliar to us, can anyone recommend a route around Boston for us?

Thanks

Graeme Arnott

09 Allure CP 31690

Re: Route Through Boston

Reply #20 –
Yahoo Message Number: 64617
You didn't mention what campground but it sounds like Normandy Farms. Use Route I-495 south off of I-95 to get around Boston.

Don Seager

2004 Allure 31046

Re: Route Through Boston

Reply #22 –
Yahoo Message Number: 64624
Thanks for the info Don, appreciate it. And you're right about Normandy Farms at least for 2 nights wanted to stay longer but they are apparently full Fri and Sat. Having the aquahot serviced in the area, diesel burner hasn't been working for about 2 weeks now, we're getting a little tired of army showers and the heat pumps.

Thanks again.

Graeme Arnott

09 Allure CP 31690

Re: Route Through Boston

Reply #23 –
Yahoo Message Number: 64642
Graeme,

I am very interested where you found a place to service your AquaHot in the area. I have not had much luck with it. Minute Man in Littleton or the Boston/Plymouth KOA in Middleboro are two other campgrounds in the area but you will likely find the same problem. The KOA is very expensive and I am starting to hear some bad reviews on it but the location is ideal.

Don Seager

2004 Allure 31046