Sauer-Danfoss FDCA

[joefromperry]

I'm looking to replace my Sauer-Danfoss FDCA control because the fan runs full on all the time. I've been talking with Source Engineering about their wax valve replacement, but they haven't  had any in stock for months,  and don't know when they'll have them again. My question: the picture of the control with the 1091140 number is my current one, and the other with number 1090943 is a possible replacement, and I need to know if they are the same. Thanks.

 

[Dr4Film]

I doubt very much that the latter one would work. I am guessing that the S/W Parameter number has a major bearing on its function.

[joefromperry]

30 minutes ago, Dr4Film said:

I doubt very much that the latter one would work. I am guessing that the S/W Parameter number has a major bearing on its function.

Yeah. I just went outside to compare the pictures with the actual unit, and the connectors are different. Thanks. Guess I'll keep looking.

 

[RIPPPA]

First off I would stay away from the Source Engineering Wax Valve system as it has a delayed response to temp changes and will allow the temp to go up faster than the wax valve can respond from what I have been told. I got into this discussion with John Davis ex Country Coach and Monaco tech a few weeks ago when I was looking for a replacement fan motor. I would call Northwest RV parts in Eugene OR and see if they can help you locate one. 541-746-9092. 
If that doesn’t work I would check with Dan-Foss dealers in the US   

[jacwjames]

My wax valve seems to respond pretty quick and keeps the engine running a decent temp.  My was valve is mounted in the upper back corner of the radiator.  It might make a difference where the was valve is mounted but I believe the wax valve in the Source kit is located in the elbow coming off the engine to the radiator, which would be the best place since it is seeing temps coming from the engine. 

The Source kit is nothing special and anyone could purchase the pieces individually.   I believe Northwest rv has wax valves, you can get an adapter to weld on the coolant elbow, and hose extensions.    If you want to save $$$ get the wax valve from Whitehouse Products and save ~1/3. 

[waterskier_1]

I have the same experience as Jim J.  I agree with Tim Boone, from a theoretical point of view.  The idea of the Electronic Controller was to anticipate when more cooling would be needed.  It took parameters from the ECU and others, like the dash A/C.  If you turned on the dash A/C, it would make the fan run faster.  If it sensed an engine load (turbo boost) it would make the fan run faster.  These examples show the intent to begin cooling BEFORE the temp rise was detected.  The wax valve can only react to a temperature rise that has already occurred.  The FDCA could have been a great device, if it were no plagued with problems.  Many have "converted" to the "old" wax valve because it is much simpler, and has worked fine for decades.  I was surprised to find that my 2005 Exec with a Detroit Diesel came with the wax valve.  I have not had any problems.  Yes, I see the temp start to rise as I climb a steep grade, but the fan does come on, and maintains a safe temp even at full throttle.  I had no problems with it on my 1997 Dynasty either.

  -Rick N.

[timaz996]

I am with Jim, I had to replace my wax valve in 2017 when I bought my coach and I bought it from White House products in the UK. Before I retired I was still living in Phoenix and would climb out of the valley with temperatures above 110° And never saw my coach get above 198. I do keep the two brass plugs so I can cap the lines going to the wax valve if it ever fails until I can replace it. 

[jacwjames]

I guess you have to decide which option is the lessor of two evils.  The thermovalve had been used in a lot of coaches and yes there have been reports of some failures but not many compared to the number of the electronic type.  I see reports of the electronic failure across a lot of different manufacturers.  And the cost to replace is high if you can even find a replacement. 

[Tom Cherry]

Don’t remember if you have posted this before or been involved in the past discussions?

Is it BROKEN as in, does NOT WORK?

It it works, as in “full speed”, have you disassembled the controller.  Many times there is moisture inside that is the cause. A RIP Member disassembled his.  He then cleaned up the corrosion. I THINK he dried out the electronic or maybe used WD-40 to purge the moisture and then electronic cleaner.  Then, to prevent future issues, he mounted the electronics or controller 180 deg from Original. That prevented any moisture or condensation l

He drove the MH for years…no a further issues. A member bought it and has not, to the best of my knowledge, had issues.

I agree with Jim.  The controller was a solution to a problem that did not exist….and was a “HIGH TECH MARKETING” selling point….  The wax controller was a robust, proven system….highly reliable….

That’s what i have read and the synopsis of countless emails on the old site and posts here….spanning 15 years.