Another Sauer Danfoss problem, maybe/maybe not

[Skykingrob]

On a recent trip to Florida I got 3 hours from my Texas home when all of a sudden started having overheat problems up to 212 degrees at 65 miles per hour in 65 degree weather. I slowed speed down and temp came down but was still over 200. I stopped at a truck stop and found the fan barely turning. I tried turning on the a/c but fan still did not speed up, presumably due to the cool temps the head pressure was not high enough to trigger the sensor to make the fan faster. As I've learned with this system there are 3 sensors, one in the CAC for air temp, one in the upper radiator hose or thermostat housing for coolant temp and one in the receiver/dryer for a/c head pressure. Since the a/c switch did not trigger the faster fan, I pulled the sensor wire off the coolant temp sensor and the fan took off like a banshee keeping me comfortably cool at 192 heading home. I know there is a fuse that can be pulled which will trigger the faster fan but couldn't remember the fuse number and couldn't find the post with that information. I had a tech with supposedly proper equipment check out the coolant temp sensor and he says its bad and what is causing the slow fan. Not sure I agree. I think it's more likely the FDC unit but when I called Berendsen Fluid in Tulsa to get the FDC, it's $1,700 and a 3 mo lead time wait. So I'm looking for the sensor just in case it might actually be bad. Berendsen forwarded a picture and parts request to Sauer Danfoss but after waiting a week, SD has not found the part. The sensor is marked "Airpak 1151". Anyone know of a source for this part?


rob
2006 Magna
Texas

[birdhunter]

Originally Posted by Skykingrob

On a recent trip to Florida I got 3 hours from my Texas home when all of a sudden started having overheat problems up to 212 degrees at 65 miles per hour in 65 degree weather. I slowed speed down and temp came down but was still over 200. I stopped at a truck stop and found the fan barely turning. I tried turning on the a/c but fan still did not speed up, presumably due to the cool temps the head pressure was not high enough to trigger the sensor to make the fan faster. As I've learned with this system there are 3 sensors, one in the CAC for air temp, one in the upper radiator hose or thermostat housing for coolant temp and one in the receiver/dryer for a/c head pressure. Since the a/c switch did not trigger the faster fan, I pulled the sensor wire off the coolant temp sensor and the fan took off like a banshee keeping me comfortably cool at 192 heading home. I know there is a fuse that can be pulled which will trigger the faster fan but couldn't remember the fuse number and couldn't find the post with that information. I had a tech with supposedly proper equipment check out the coolant temp sensor and he says its bad and what is causing the slow fan. Not sure I agree. I think it's more likely the FDC unit but when I called Berendsen Fluid in Tulsa to get the FDC, it's $1,700 and a 3 mo lead time wait. So I'm looking for the sensor just in case it might actually be bad. Berendsen forwarded a picture and parts request to Sauer Danfoss but after waiting a week, SD has not found the part. The sensor is marked "Airpak 1151". Anyone know of a source for this part?


rob
2006 Magna
Texas

Colton Truck used to have the sensors you want. When my danfoss coolant sensor failed years ago the fan was on high all the time. It's easy to check the sensors, there's a resistance versus temperature chart for those, I don't have it handy, maybe someone else does.

[Smitty77]

For the first 5-6 years we had our Allure, I found out after unusual fan behavior, that the harness plug connections had become pretty messed up. (On our 04, raw FCU was mounted low on a rear frame, and the road grime and water was tossed up on to the unit and the harness from the Driver side Tag and probably some from the Dual.). I was able to move the FCU up a little, and then used Electronic Cleaner to clean the Male and Female plugs. Then once it was all dried, I dabbed a bit of dielectric grease on the male, and a bit into the female. The FCU started behaving correctly again. I did a yearly maintenance of the Harness after that, to keep it clean.

When my FCU did go out, I decided to go with the Source Engineering Thermal Valve. Was pleased with this, as temps were well controlled, and I feel on average - I had a bit more of the ISL's HP going to the Drive Wheels vs the Cooling Fan. (Of course with probably a C-13 in your Magna, power and torque is not as much of a concern!).

Best,
Smitty

[Skykingrob]

Birdhunter, I assume you mean Colton Truck in California. I talked with them and they have no idea what I'm even talking about on the part. Am I correct, California? If so, do you have a name?



Rob

[Skykingrob]

Birdhunter, I assume you mean Colton Truck in California. I talked with them and they have no idea what I'm even talking about on the part. Am I correct, California?

I did talk to Colton Truck in Montrose CO and they suggested it might actually be "Airpax 1151" after showing him the picture. So I traced that down and found a company by the name IBS who traced it to a company by the name Airpax which was bought out by Sensata. Sensata has discontinued the sensor and there is no crossover number for a newer one.
Does anyone have the temperature vs resistance number Birdhunter was talking about to check the sensor to see if it's bad?

Rob

[birdhunter]

Originally Posted by Skykingrob

Birdhunter, I assume you mean Colton Truck in California. I talked with them and they have no idea what I'm even talking about on the part. Am I correct, California?

I did talk to Colton Truck in Montrose CO and they suggested it might actually be "Airpax 1151" after showing him the picture. So I traced that down and found a company by the name IBS who traced it to a company by the name Airpax which was bought out by Sensata. Sensata has discontinued the sensor and there is no crossover number for a newer one.
Does anyone have the temperature vs resistance number Birdhunter was talking about to check the sensor to see if it's bad?

Rob

Rob, Yes I meant Colton Truck in California. I got the coolant and air temp sensors used in the Danfoss system from them but that was probably 14 years ago. I have a couple more I purchased just a few years ago from Berendson. That is for sure.

https://www.bfpna.com/aboutus/SystemsServices.aspx

[birdhunter]

Originally Posted by Skykingrob

Birdhunter, I assume you mean Colton Truck in California. I talked with them and they have no idea what I'm even talking about on the part. Am I correct, California?

I did talk to Colton Truck in Montrose CO and they suggested it might actually be "Airpax 1151" after showing him the picture. So I traced that down and found a company by the name IBS who traced it to a company by the name Airpax which was bought out by Sensata. Sensata has discontinued the sensor and there is no crossover number for a newer one.
Does anyone have the temperature vs resistance number Birdhunter was talking about to check the sensor to see if it's bad?

Rob

Here is the chart

[CntryCoachRV]

Originally Posted by Skykingrob

Birdhunter, I assume you mean Colton Truck in California. I talked with them and they have no idea what I'm even talking about on the part. Am I correct, California?

I did talk to Colton Truck in Montrose CO and they suggested it might actually be "Airpax 1151" after showing him the picture. So I traced that down and found a company by the name IBS who traced it to a company by the name Airpax which was bought out by Sensata. Sensata has discontinued the sensor and there is no crossover number for a newer one.
Does anyone have the temperature vs resistance number Birdhunter was talking about to check the sensor to see if it's bad?

Rob

I would go with Smitty’s solution. Be rid of the old hard to get technology which probably should never have been used to begin with. The wax valve is a simpler technology and more importantly is easy to acquire.

[CntryCoachRV]

Country Coach Fan Test

Before you make any assumptions, test the fan sensors using the following instructions. You should also check the IRV2 Country Coach forum regarding radiator issues which are common with mid 2000 models.

Take the following measurements with Ignition OFF and Engine COLD.

Climb under coach and disconnect the 6 Pin Fan Controller Connector. It has a "latch" on top of connector you release and hold open while pulling connector apart.

Wipe connector clean so that you can see the alpha markings ABCDEF denoting wires/pins.

The following measurements are taken on the Engine Side of the Connection not the Controller Side.

Wire/Pin A&B go to your Dash Air Conditioner Relay
Wire/Pin C&D go to your Engine Coolant Sensor
Wire/Pin E&F go to your Air Temp Sensor

With Multi-Meter set on OHMS

Measure across C&D should = 1.2K to 3K OHMS
Measure across E&F should = 1.2K to 3K OHMS

If so, these 2 sensors are not your problem.Hope this helps.


Airpax/Sensata the mfg. of the Coolant & Air Temp Sensors are no longer selling these parts to the public, they only sell them to the Sauer DanFoss or Sauer DanFoss authorized dealers. Both Colton Truck 909-825-4080 and Specialty Logistics 541-515-6651 carry them in stock or have them on order for stock.

Original Airpax/Senata "Coolant Sensor" 5024-0184 NOW: 1090173
Orignial Airpax/Senata "Air Temp Sensor" 5024-0185 NOW: 1090174


procedure for testing you "coolant temp sensor" and "air temp sensor".

1. Crawl under coach and locate your Sauer Dan Foss "Fan Controller" it should be mounted near the fan motor and you'll see a 2 pin power plug/connector and a 6 pin plug/connector.

2. Keep Ignition OFF

3. Disconnect the 6 Pin Connector and you want the engine side of the connector not the side that goes into the controller. The engine side of connector will have small alpha letter A thru F.

4. Take your multi-meter set it on OHMS.

5. Place you Multi-Meter probes in C & D "Coolant Temp Sensor" and record OHMS, now place probes in E & F "Air Temp Sensor" record OHMS

6. With a cold engine,,,i.e. in the morning both should read 1.2K to 3.0K.

Invluded in chart previously posted….example at coolant and air temperature of 80 degrees the OHM reading would be right at 2.0K.

These sensors are manufacutred by Airpax/Sensata the Coolant Sensor is Pt.#1090-173 the Air Temp is Pt.#1090-174 both Colton Truck in Calif. and 909-825-4080 and Specialty Logisics 541-515-6651 stock these.

[ronandsue74]

The attached file is an option for replacing the Danfoss controller. This setup has worked flawlessly for me over the last four years and 20k+ miles.
I thought I would repost this file.
CCRider

[Skykingrob]

Thank you to Country Coach RV and RonandSue 74 for such great complete information. As soon as the ice gives way to warmer temps here in Texas, I'll use the info to get into it.



Rob
2006 Magna
Texas

[StubbyBus]

Originally Posted by birdhunter

Here is the chart

Is there a second page of that chart? That one ends just before it gets to the good part.

Thanks,
Jeff

[birdhunter]

Originally Posted by StubbyBus

Is there a second page of that chart? That one ends just before it gets to the good part.

Thanks,
Jeff

Sorry Jeff, that's all I've got!

[Ozzsp250]

I came across this but can't access it to see the chart

Hydraulic Fan Test Procedure - Country Coach Forums.
https://www.countrycoachforums.com › ...
identified by having only one plug to the hydraulic fan controller valve. ... ohms Inlet air sensor (see resistance values attached). Fan Functions ...


https://www.sauerbibus.de/fileadmin/...e_Control_.pdf

Based on the above looks like this is the chart:

https://downloads.greystoneenergy.co...arts/RT-08.pdf