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Hydraulic Fan Won't Operate

Yahoo Message Number: 95693
I'm on the road and my hydraulic fan won't come on. I understand if I disconnect the controller it will default to high but where is that connection? I'm running 228 degrees, what is too hot?

Jim Coshow

2005 Inspire 51501 Cat C-9

Re: Hydraulic Fan Won't Operate

Reply #1 –
Yahoo Message Number: 95694

Jim:

The 3 wire plug is at the controller on the left rear of the coach, near the radiator. Another option is the fan controller & fuel heater fuse in the box in the bay under the driver seat,
The engine should shut down at about 224 degrees. Overheating could cause a blown head gasket and other problems.
There could a number of things causing your problem, I'd get a shop to run it down. A Cat shop should be able to handle the job.

John Beach

06 Allure 31309, C9

Re: Hydraulic Fan Won't Operate

Reply #2 –
Yahoo Message Number: 95696
on the driver's side. on the back corner of the cooler closest to the bumper. There should be a triangle 3 wire plug. It should be connecting to the controller. Some have a 6 wire plug depending on how the cooler is controlled. Unplug and it should go full speed.

Buddy Bordes

06 Inspire 360 51887

Re: Hydraulic Fan Won't Operate

Reply #3 –
Yahoo Message Number: 95700
Jim

Last year I had overheating and the fan would not come on without disconnecting the harness at the radiator. I cleaned the connector with electrical contact spray cleaner, squeezed some dialectric grease on the contacts and am still good after about 8 months. It is worth a shot.

Dan 2006 Allure 31348

Re: Hydraulic Fan Won't Operate

Reply #4 –
Yahoo Message Number: 95701
Jim,

I have experienced that problem as well. It is my opinion that an engine temperature of 224 degrees is much higher than I would like to see. I am surprised that your engine dash amber warning light did not come on. I am not sure, but at that temperature you might be close to an engine shut down red light. My fan controller is a Danfoss computer unit that controls the hydraulic cooling fan operation. There are two sensors on the engine that provide coolant and air temperature data to the computer. Your problem could be with the sensors or the computer unit. Danfoss is not a company easy to deal with. If you order a new computer and sensors it will cost you approximately $1200. They will not sell to you direct. You must go through one of their dealers. The biggest problem is that the unit has a 6-8 week delivery time unless you want to pay extra for expedited service and that will cost you an additional $200-300.

Buddy and Jim are correct about disconnecting the plug at the rear of the coach at the aft end of the radiator and it will put the unit in the default high speed operation. I drove my coach some 300 miles with the radiator fan in the high speed default mode. On my coach the engine temperature dropped from 212 degrees to approximately 170 degrees. At the 212 degree point is where my engine amber warning light came on. Jim is also correct about the fuse under the driver seat in the electrical bay. You can locate and pull the fuse and it will put the fan in the default high speed mode. I took it one step more by installing an "off-on" switch on the dash to enable the driver to manually control the cooling fan from the driver seat. This is much easier than pulling the fuse or disconnecting the plug at the rear of the coach. If you have the time I would suggest that you replace the two sensors before replacing the computer unit. The two sensors cost approximately $110. If that does not fix the problem then the computer unit will need to be replaced. If you need additional information feel free to email me at jgnylint@...

Jon Gullette

2004 Inspire #51008

Re: Hydraulic Fan Won't Operate

Reply #5 –
Yahoo Message Number: 95703
Jim, et.al.

I swapped out the Saur Danfoss controller for the thermal wax valve system over two years and 25,000 miles ago. I can report excellent results with nary a glitch in all that time and all those miles. My temps run just a bit too cool at about 189 degrees and tranny temps follow closely. Long pulls on grades will see about 196 and a very ocassional 205. In short I have been very pleased with the system.
Lyle Wetherholt
04 Intrigue 11740

Re: Hydraulic Fan Won't Operate

Reply #6 –
Yahoo Message Number: 95705
I also swapped out my fan controller with the wax melt control. It has worked very well and my water temps hold around 189 also except for long hills in hot weather, then it will go up to around 205 or so.

Norm

2004 Intrigue #11773

Re: Hydraulic Fan Won't Operate

Reply #7 –
Yahoo Message Number: 95720
Should this ever happen to me, I'd like to be prepared to act....... So...... Please tell us where you got it, how difficult --- time, etc., to install the change of the units. Also please let us know the costs involved in making the change.

Sounds like a very interesting solution to a problem experienced by many of us.

Thanks

Den 2001 42'Affinity #5972

Re: Hydraulic Fan Won't Operate

Reply #8 –
Yahoo Message Number: 95722
I have a 2001 (new to me) Affinity with the C-12. How do I know when the fan comes on? Should I hear it? My coolant temperature runs in the 200-215 range.

Richard

2001 CC Affinity

Re: Hydraulic Fan Won't Operate

Reply #9 –
Yahoo Message Number: 95724
Richard,

I have the C12 in my Magna also. I could hear the fan in my 33' Allure but cannot hear the fan in my 42' Magna. Your temperatures are the same as mine. These engines are designed to run from 195 - 220.

Good luck with your new coach.

George in Birmingham
'03 Magna 6298
George in Birmingham
2003 Magna 6298

Re: Hydraulic Fan Won't Operate

Reply #10 –
Yahoo Message Number: 95727
You can pull the fuse and achieve the same effect.

Larry 03 Allure 30856

Re: Hydraulic Fan Won't Operate

Reply #11 –
Yahoo Message Number: 95728
Richard, your temps sound fine but here is a simple test. On start up when the engine is cold place a large piece of cardboard over the radiator grill (intake). Hold it about six inches away from the grill. If it snaps out of your hand then your fan is running high and should not at that engine temp. If there is no pressure to pull it out of your hands then your fan is either off or at idle speed. This is not a comprehensive test and there are other diagnostics that can give you more information but this is a quick and easy to see if your fan is on high speed.
Lyle Wetherholt
04 Intrigue 11740

Re: Hydraulic Fan Won't Operate

Reply #12 –
Yahoo Message Number: 95735
The problem is most likely caused by either the hot water sensor or the hot air sensor on the engine. According to John Davis nearly 80% of the time the problem is not the fan controller but one of the sensors. Many fan controllers are replaced unnecessarily and at great expense when one of the sensors is actually the problem. I found that the hot water sensors failed twice on my coaches. Call or email John Davis (jdrv1@...) and he will help you and sells the sensors cheaper than any other source I have been able the find.

Gene Merryman
2006 Intrigue
CC #12005
 

Re: Hydraulic Fan Won't Operate

Reply #13 –
Yahoo Message Number: 96044
Lyle,

Do you have a source for the thermal wax valve system you referred to?

Thanks,
Jim