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Fan Controller - 05 Inspire

Yahoo Message Number: 113875
Greetings campers!

I've been troubleshooting an erratic Danfoss fan drive controller for a while now, with great assistance from the Danfoss folks. I'm pretty well convinced there is nothing wrong with the controller itself, rather the input from the coach.

Lately, the fan is always on, from cold startup to shutdown.

The 12 volts from the chassis fuse panel to the FDC is intact.

The 05 C-9 Inspire uses a single input from the engine - coolant temperature - to regulate the fan. Can anyone tell me if the temperature signal comes from the thermostat or from the ECM? It is a single wire and I'm having difficulty tracing it.

I appreciate any assistance or advice you might be able to share.

Jay 05 Inspire 51457 original owner

Re: Fan Controller - 05 Inspire

Reply #2 –
Yahoo Message Number: 113877
Jay:

Check the "Fan Control Type" in the engine ECM; it should be set to On/Off DC, if not the controller operation maybe

intermittent.

John Beach06 Allure 31309

Re: Fan Controller - 05 Inspire

Reply #3 –
Yahoo Message Number: 113886
Replace the Sauer Danfoss fan control with a Wax valve. You are on borrowed time for an "overheating" event, and perhaps breakdown on the side of road. Sauer Danfoss fan control is ridiculously complicated with old mid 90's technology...For example, to troubleshoot it, you use Windows 95...

Greg
06 Magna

2006 Magna Rembrandt C13
2016 Jeep GC toad

Re: Fan Controller - 05 Inspire

Reply #4 –
Yahoo Message Number: 113890
My understanding is the thermostat signal inputs to the ECM where it is processed. The ECM compares the the temperature to the fan controller parameters and outputs the fan speed. The fan controller parameters has two settings. Always on or variable, default is variable.

Have played with both parameters and finally settled on variable with some over heating on high load, high ambient temperatures.

Mark
07 inspire 51985

Re: Fan Controller - 05 Inspire

Reply #5 –
Yahoo Message Number: 113896
I meant to add, for the last two or so years of my OEM FCU, when it would act up, I would unplug the harness from the FCU, spray and clean with electrical cleaner, spray Deoxit Gold, and reconnect. And I'd be good to go for awhile again. Did this at least 3 times when I had a problem, and just added a yearly cycle of doing this to my maintenance cycle.

Smitty
04 Allure 31017

ISL CAPS ERA with:
-Source Engineering Wax Valve
-Bypassed Lift Pump with FASS pump
-New proud owner of a Steel Stamped Oil Pan, after Composite pan cracked
-EGT sensor installed into replaced cracked Exhaust Manifold (Sure like knowing the temp!)
-Optilube into each fuel fill up
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Fan Controller - 05 Inspire

Reply #6 –
Yahoo Message Number: 113897
I know some coach owners of CC's and SOB's too, after multiple troubleshooting and or replacements of the FCU's over the years. Have gone made one of the two changes:

1) Go the fuse box below the driver's seat, and splice a cockpit controlled toggle switch into the line that feeds power to the FCU fuse. They then manually control 'On/Off' of the fan, using the temperature gauge as their guide. Usually these are with failed FCU's, so when the toggle the switch on, the fan defaults to High. (Caution: This puts temperature control into the hands of the driver. Damage could occur if this driver control unit (us owners) fail in this monitoring and activation of the switch:)!)

2) As Greg L, said, use the Wax Valve solution. Source Engineering did ours on our 04 Allure with ISL, and I've no complaints with their workmanship, or how it functions. I like the 'KISS' approach to fan speed.

I know that Dan F. with a C9, just went thru a process of repairing his unit again. He preferred to keep the FCU approach, and got one of their new 'universal' units. And worked with them ad CAT to finally get the 'universal' to properly activate with his coach.

Best of luck to you,
Smitty
04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Fan Controller - 05 Inspire

Reply #7 –
Yahoo Message Number: 113933
Thanks to everyone who took the time to respond to my query.

The fan controller was bad. I had been carrying a new Danfoss ever since the original had been acting up, just in case it failed completely. I didn't want to throw an expensive part at the problem if there was a simpler and cheaper solution. There wasn't.

The new controller works like a champ, and I don't have to listen to the fan anymore.

Safe travels,

Jay
05 Inspire 51457

Re: Fan Controller - 05 Inspire

Reply #9 –
Yahoo Message Number: 113949
Brian, the Sauer Danfoss controller regulates the engine cooling fan, which is variable speed, hydraulically driven.

Jay 05 Inspire 51457
 

Re: Fan Controller - 05 Inspire

Reply #10 –
Yahoo Message Number: 113951
When I had what I thought was a fan controller problem in June of 2015, it actually turned out to be an electrical connector corroded that just needed cleaning up. Peterson CAT in Eugene, found the problem in 10 minutes with an ohm meter - Jake the shop foreman really new the system. After that I never had another problem in the next 2 years and its still going fine 3 years later. What I wanted to share was that the CAT shop foremen told me was that the batteries in the CAT ECU's usually start failing around 10 to 12 years - which can cause intermittent setting problems and eventually starting problems. He said our ECU battery looked ok, the voltage was slightly low, but not at a point to fear. He told me it would be far cheaper to not have to replace an ECU in a crisis, there are good rebuilt ones to be found as a possible backup or at least know where to get one. Also, its far cheaper to transfer settings from a working ECU than to start over.

All of this to say that Jake at Peterson CAT really knows the Sauer Danfoss fan controller system and its nice when you find people who can coach you along the way. Also, thanks to this group, its one of the reasons we'll buy another Country Coach...

Mike

Michael St. John

former owner, 2005 CC Magna C13 #6501, getting close to buying another in the next 6 to 8 months.