Fan controller update

February 02, 2012, 09:50:41 pm

My controller has been out of service for several years now and I have been cycling the fan using an on/off switch but was tiring of the added workload and yes I did run hot on a few occasions. Added to that the hydraulic solenoid was leaking so it was time for me to bite the bullet. I orered the controller from Berndensen and had it shipped to my RV garage to await our return for the summer. As I am quite aware that many of the controllers are turning up not programmed, I was somewhat concerned as this garage does not have the programming tools nor were they that familiar with its proper operation. I left instructions to make sure they take the bus out for a long enough ride to make sure it was cycling properly. They assured me that this was done so time to go for my 200 mile trip back home. It seemed ok at first as no fan with cold engine and it would switch to slow speed when the A/C needed it. I turned off the A/C and waited for it to come on when engine temp reached around 190. 195...no fan...200...205...better pull over. Well the A/C will control it so I got home with A/C running.
Of course the first thing that strikes my mind is the darn thing isn't programmmed but let me do the sensor checks. Well both the air and coolant sensor show resonable resistance as per the chart for the current temperatures so maybe it is the controller. Of course I would have to remove it to ship it somewhere so I decided to do more testing before I did that. I found a variable resistor with values that would match what the sensors would transmit under operating temperatures and plugged him in. Wow...the fan starts running slow and switches to high right where its supposed to. Back to the sensors and when I test the air guy he seems very close to what its supposed to be sending. Lets check the coolant sensor. I remove him from his fitting on the return rad pipe and get ready to stick a plug in his place and what?? No coolant. Hmmm...do I have an airlock or is that pipe empty or low on fluid? No there is a membrane of rust or scum blocking the sensor entrance. Sensor dry as a bone. Screwdriver popped right through it and coolant gushes out. Coolant sensors like to be immersed in liquids. Problem solved. Happy fan now.

Ed McManus....'02 Intrigue.....11361

Re: Fan controller update

Reply #1 – February 02, 2012, 10:24:27 pm

Yahoo Message Number: 77232

Now that I think about your coolant discovery, I wonder how many controllers have been changed without the need.
I do know that how controllers are programmed depends on the part number. A Sauer Danfoss engineer told me that they are all programmed before they leave the factory so no need to pay someone big bux to program one.

Don

'02 Intrigue #11427

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