Sauer Danfoss Fan Controller Option

[ronandsue74]

Butterballo6, I mounted my controller in an exterior electrical box, photo attached, I got from Home Depot. I drilled holes in the top to allow for heat to escape. I glued a piece of cheap filter media on the inside of the box where I drilled the holes to keep dirt out. I have not had any heat issues with my setup. I quite sure you won't have any heat issues in your mounting location.
Ron Jacobs
CCRider

[Mlfiedler]

Originally Posted by ronandsue74

I'm sure the wax valve is a perfectly acceptable solution.
I wanted to maintain the high speed override switch I installed as well as the air conditioner high/low pressure switch.
CCRider

Ron, I’m following your lead here. The PWM- speed control is a cool adoption! I’ve been playing around with ways to implement that on my rig.

But somehow, I’m missing the high-speed over ride, and the A/C switch. Are they reflected in your schematic? Is “HS override” a manual switch, shutting off power to solenoid to shift to max fan? Does your “A/C high-low” function similarly, maybe running the output of the trinary switch to a relay that interrupts power to the solenoid?

[ronandsue74]

The override switch is something I installed years ago. Yes its independent from the Danfoss controller option. I don’t have the ac on a switch, my fan rpm is high enough at low speed to compensate. I estimate my low fan speed to be around 1000 rpm at 9.9 volts. I just drove 1200 miles to Florida and my System worked flawlessly.

[CountryFit]

My engine has a cold heart, always staying at 160 degrees give or take in normal driving. The highest temp I have seen was 180 deg on long and steep uphill. A few years back I replaced the thermostat it didn't do a thing. At idle, even engne is cold, it turns slower, at 1000 rpm it gets faster, at 1500 or up, it roars like crazy. Maybe the hydraulic control works as supposed to, but don't like it. I'll probably go the same way Ron did. Thanks Ron for sharing it.

[CountryFit]

Just want to insert this in case anyone else runs into this 160 vs 180 degree dilema. I found another RVer having the same 160 deg thermostat in this thread, his ID is Lenp:

https://community.fmca.com/topic/967...e-cummins-isl/

[Gl1800]

CC rider
Could you send me the info for install on the Sauer Danfoss Fan Controller Option ? I have ordered the parts. Thanks for the option to not have to order the expensive new controller. Not sure we could get another new Sauer Danfoss Fan Controller with preprogram since we don't have the old parts availability.Going to install this system before I have another failure.

[Butterball06]

Hi Ron,

Been running your setup for about 2500 miles. So far so good. Mileage is better. Just curious about about running AC in HOT Texas. Have you an idea for bypassing your set up or adding something to kick the fan up when running (AC) in high temps. I am a little concerned of AC compressor failure due to the fan not kicking on when AC is turned on. I understand when 205° coolant is reached the fan will come on. But, how about AC operating below that temp?

Thanks,

B Ball

[426smartin]

[Mlfiedler]

Quote: "I am a little concerned of AC compressor failure due to the fan not kicking on when AC is turned on."

I'm with you, having the fan respond to your A/C seems worth while. An option might be add a simple 12v relay, with the power to your fan solenoid hooked to tabs 30 and 87A, (the normally closed terminal) and the "trigger wire" on tab 86 coming from the compressor clutch switch wire. Then when A/C kicks on, the power to your fan solenoid is interrupted, and the fan goes to full on.
Have I done this? Not yet . . . but here in Washington State, we haven't needed A/C in a while. Its coming.
Amazon has lots of relays.
Just be sure to get a 5-terminal version. 4-pins lack the 87A.

[phays]

I'm confused by this discussion on how the Sauer Danfoss fan controller behaves when the OTR A/C is being used. On my 2000 Magna with CAT C-10 the Sauer Danfoss input is set to turn the fan on high speed when the compressor is operating. The trinary switch on the A/C system is the control sensor that causes the change.

[Mlfiedler]

What I understood B BALL to be describing, is adopting a somewhat simple control strategy once the Sauer Danfoss has "expired". Some units, having been replaced, only last 3 to 4 years, so folks have explored less costly, perhaps simpler and more dependable ways to hush that screaming fan. (Fail safe mode calls for full speed any time the Sauer unit experiences a fault.)

[phays]

OK. I understand the thread now. I saw a thread someplace where a wax valve was used and the person added a solenoid valve that could be switched on when desired to force the fan to high speed. I don't know the plumbing necessary to do that but a manual switch could be used or the existing circuit from the A/C circuit could be configured to switch the solenoid.

Just an alternative approach.

[ronandsue74]

Butterball06,
I have installed a manual override switch on my driver control panel/transmission control panel. This allows me to switch my fan too high whenever I want. I run my fan on high as I'm approaching mountain grades or running my air conditioner in extreme temperatures. Just today, I came home from a 1,700 mile trip from Florida. My engine temp & air conditioner worked perfectly the entire trip.
Ron Jacobs
CCRider

[RV Driver]

Originally Posted by Mlfiedler

...Fail safe mode calls for full speed any time the Sauer unit experiences a fault...

Yes, that’s what the Danfoss literature says. But don’t believe everything you read. Guess how I know this. We had to limp home from South Dakota to Ohio when the Danfoss unit failed - AGAIN - with the fan stuck on low speed. Good thing there are no big hills on that route.

I solved the problem a couple of years ago with the Source Engineering Thermal Valve Conversion (the wax valve.) No switches, no extra wires, just reliable and proper fan control - FINALLY!