Flyinhy Posted January 4, 2023 Share Posted January 4, 2023 Hi guys and happy New Year. I'm slowly but surely fixing things on this old coach. I've moved on to the hydraulic fan now and I'm scratching my head a little. Maybe someone can point me in the right direction with this one. Okay.....2001 sig Exec 500 ISM hydraulic fan. Runs at full speed all the time. I went to check flow at the wax valve yesterday and noticed a small electrical coil on a valve before the wax valve itself ....that I've overlooked before. I took the coil off and boom, the fan goes to idle. I looked at my schematics and I can't find the wiring for this coil. I traced it back to a relay in the rear run box on the left. As far as I can tell it gets +power from battery and the ground is the "excite" signal from either the thermostat sensor and or, the intake sensor? I unplugged both sensors and still have full speed fan. What am I missing? 1 Link to comment Share on other sites More sharing options...
Solution vito.a Posted January 4, 2023 Solution Share Posted January 4, 2023 I'm not certain on the year, but Cummins went to an electronically controlled fan in the early 2000's. Our 2004 uses a Sauer Danfoss electronic fan controller. It takes input from the engine ECU. Great idea but they often fail. The real problem is new electronic fan controllers are not available. I converted our system to a Sauer Danfoss mechanical wax valve from White House Products in England. This is a link to a very long thread on IRV2. It has great info with pictures. https://www.irv2.com/forums/f115/fan-stuck-wide-open-376611.html Attached is a picture of the OEM Sauer Danfoss electronic fan controller. 1 Link to comment Share on other sites More sharing options...
Flyinhy Posted January 5, 2023 Author Share Posted January 5, 2023 I read the whole thread and I'll do some more research. I found this in my second set of schematics. Link to comment Share on other sites More sharing options...
Flyinhy Posted January 8, 2023 Author Share Posted January 8, 2023 Okay, I've spent most of the morning looking for this sauer "fan controller". Does anyone know where this electronic box should be? If I have it, it's well hidden. I see the wax valve. I see the small electrical valve with a 12v coil on it that controls the flow and its not what is described In my schematics. it says engine compartment......that's it. The small valve has two wires coming off the coil not the 6 wires that are described for the FDCA. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted January 8, 2023 Share Posted January 8, 2023 10 minutes ago, Flyinhy said: Okay, I've spent most of the morning looking for this sauer "fan controller". Does anyone know where this electronic box should be? If I have it, it's well hidden. I see the wax valve. I see the small electrical valve with a 12v coil on it that controls the flow and its not what is described In my schematics. it says engine compartment......that's it. The small valve has two wires coming off the coil not the 6 wires that are described for the FDCA. If you have a wax valve you shouldn't have a Sauer electronic valve. Pretty sure it's one or the other. Link to comment Share on other sites More sharing options...
Frank Bergamo Posted January 8, 2023 Share Posted January 8, 2023 This is the wax valve in question. Is this what you have? https://www.whitehouseproductsltd.com/products/hydraulic-motors/hyd-gear-motors-fan-valves/dynamatic-fan-drive-motors-valves/553-1-09857-210-thermo Link to comment Share on other sites More sharing options...
Flyinhy Posted January 8, 2023 Author Share Posted January 8, 2023 Okay, I'm officially confused on how this system works now. Link to comment Share on other sites More sharing options...
Tom Cherry Posted January 8, 2023 Share Posted January 8, 2023 Here is a lot of info for you. The theory was that the ECM was a perfect candidate or “brain” to control hydraulic fluid. OPPS, the valve had issues. Some also were mounted where they got wet. Many of our members salvaged them and cleaned the connectors and mounted the terminal section on the bottom….just reversed them. First thing to find out…..do you HAVE the older Wax Valve, I can’t tell from the print (picture) what the circuit is. one of the best resources is Source Engineering. Scott and Jim are former Monaco employees and have a “retrofit” kit. Basically, if you have the older WAX VALVE CONTROLLER, they should have a replacement. If you have the Sauer Deloss, then they can sell you a replacement wax controller kit. Many folks swear by the original design. Read the above and then call them (Google them) and they will walk you through identification of what you have and what you need. Good Luck 1 Link to comment Share on other sites More sharing options...
jacwjames Posted January 8, 2023 Share Posted January 8, 2023 I'm confused also as to what the solenoid valve is and how it might control the system if you have a thermovalve!. Do the hoses from the thermovalve go to the switching device on the motor. There is a pretty good writeup in my manual on my thermovalve. You may check yours and see what it says. When I was having trouble with my system I contact Monaco tech support, this was when they actually would respond to an email and talk to you a phone. The tech (Jesse Covington) told me to do two tests I plugged both lines and the fan ran wide open. I then put a union in between both hoses and the fan ran at an idle. Based on this the thermovalve was bad. I bought one through Whitehouse Products out of the UK, best price and fast shipping. 1 Link to comment Share on other sites More sharing options...
Flyinhy Posted January 8, 2023 Author Share Posted January 8, 2023 Yes, One hose comes off the wax valve to the 12v coil. I can take the coil off and the fan runs at idle. So that tells me that valve is working. That also tells me I have flow through the wax valve .....correct? I think I have some sort of experimental system because I haven't seen or read anything that describes my system exactly. What turns on the 12v coil ? The million dollar question. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted January 8, 2023 Share Posted January 8, 2023 10 minutes ago, Flyinhy said: What turns on the 12v coil ? The million dollar question. A switch for the driver maybe? Perhaps a previous owner installed the 12v valve so he could turn it off or on. Link to comment Share on other sites More sharing options...
Frank Bergamo Posted January 8, 2023 Share Posted January 8, 2023 On 1/4/2023 at 4:54 AM, Flyinhy said: I went to check flow at the wax valve yesterday and noticed a small electrical coil on a valve before the wax valve itself ....that I've overlooked before. How about removing the valve before the wax valve. Then replace the wax valve itself with a new one, back to original configuration. 1 Link to comment Share on other sites More sharing options...
jacwjames Posted January 8, 2023 Share Posted January 8, 2023 So I wonder if this was installed to make the fan run WAO, possibly reduce a heating problem. Can you trace the wires from the solenoid, any chance they could go to some sort of temp sensor that controls the solenoid valve and/or a switch to the dash? I'd suggest bypassing the solenoid and do both the tests I listed above to confirm if the thermovalve is working as it should. Link to comment Share on other sites More sharing options...
Frank Bergamo Posted January 8, 2023 Share Posted January 8, 2023 2 minutes ago, jacwjames said: So I wonder if this was installed to make the fan run WAO, possibly reduce a heating problem. I think this is exactly what is going on. Also, working around a failing wax valve. 1 Link to comment Share on other sites More sharing options...
Flyinhy Posted February 9, 2023 Author Share Posted February 9, 2023 The email I received today. Unfortunately, we have limited information regarding the construction of this RV, as it was built by the previous Monaco Coach Corporation which closed under bankruptcy in 2009. However, according to our service manager: Should have a thermovalve MCC # 2136 (#11 in picture) that is controlled by an electric thermo solenoid kit MCC # 07010906 (in picture #1 down low at the left corner) which is then controlled by the ECM of the engine. If the engine has been re-flashed then the programming has probably been set incorrectly. The other thing is that valve kit could be bad and needs to be replaced. Okay, so according to them, the "wax"(#11) valve is controlled by the thermo solenoid mounted on the side of the radiator (#1)which is controlled by the ecm. Which makes me even more confused. If I take the coil off the single action valve (#1) and the fan goes to idle, shouldn't the wax valve keep the hyd oil from flowing if it's not up to temp.....unless it's stuck open? What would be the downside of installing a separate temp sensor that activates the single action valve on the side (#1)? There The only tmhim g we can suggest is to bring it to Coburg to have us check the ECM parameters and the valves. Attached are the prints we could find. Link to comment Share on other sites More sharing options...
Ivan K Posted February 9, 2023 Share Posted February 9, 2023 (edited) Charles, I have what appears to be the same solenoid valve with our ISM. I did not have a reason to dig into the exact function but my imaginary understanding was that the valves proportional opening/closing is controlled by pulse modulated signal from the ECM. I may be totally wrong but I based it on a section in my ECM image. Fan Control"Air Conditioner Pressure Switch Controls Fan","Enable""Drive Ratio","1.19""Fan Accessory Switch","Disable""Fan On During Engine Braking","Enable""Fan Type","On/Off""Maximum Speed","2500",RPM"Pulse Width Modulation Frequency","60",HzFan Control - Air Conditioner Speed Control,Disable Only now I noticed the switching valve, no clue what that does. Edited February 9, 2023 by Ivan K 1 Link to comment Share on other sites More sharing options...
Flyinhy Posted February 9, 2023 Author Share Posted February 9, 2023 (edited) Thanks Ivan, saved the day again. I'm sure there's more involved , intake sensor, water sensor , all signals come through the ECM , that makes sense.... I wish I had access to insite to look at everything but unfortunately I may have to call cummins for this one. Edited February 9, 2023 by Flyinhy Added comment Link to comment Share on other sites More sharing options...
dl_racing427 Posted February 9, 2023 Share Posted February 9, 2023 13 hours ago, Flyinhy said: The email I received today. Unfortunately, we have limited information regarding the construction of this RV, as it was built by the previous Monaco Coach Corporation which closed under bankruptcy in 2009. However, according to our service manager: Should have a thermovalve MCC # 2136 (#11 in picture) that is controlled by an electric thermo solenoid kit MCC # 07010906 (in picture #1 down low at the left corner) which is then controlled by the ECM of the engine. If the engine has been re-flashed then the programming has probably been set incorrectly. The other thing is that valve kit could be bad and needs to be replaced. Okay, so according to them, the "wax"(#11) valve is controlled by the thermo solenoid mounted on the side of the radiator (#1)which is controlled by the ecm. Which makes me even more confused. If I take the coil off the single action valve (#1) and the fan goes to idle, shouldn't the wax valve keep the hyd oil from flowing if it's not up to temp.....unless it's stuck open? What would be the downside of installing a separate temp sensor that activates the single action valve on the side (#1)? There The only tmhim g we can suggest is to bring it to Coburg to have us check the ECM parameters and the valves. Attached are the prints we could find. This is to help clarify your understanding of the system. Regardless of which system you have, the wax valve or the solenoid valve, it regulates bypass flow past the fan motors. That valve is open at fan low speed and closes to force all the fluid through the fan motors for high speed. I agree that there should not be both a wax valve and a solenoid valve in the system. I think you're calling the solenoid valve a wax valve. Wish I could be more help. I'm sure others on this site will help you sort it out. Link to comment Share on other sites More sharing options...
Flyinhy Posted February 9, 2023 Author Share Posted February 9, 2023 David.....That's my question. The wax valve in Ivan's diagram is called "temp sensor" and the solenoid valve w/ 12v coil is "F3". Why would it have both? A failsafe maybe? Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 9, 2023 Share Posted February 9, 2023 (edited) Charles, When you mentioned " wax valve " that got my attention. The wax valve technology goes way back before electronic engines, and it is considered by many to be pretty much foolproof. When electronics came to diesel engines Monaco and others began using electronic valves which seem to be more problematic. One ex-member Bill G ( RIP ) found his problem was because Monaco mounted the controller with the wires in an upward manner which over time allowed moisture to creep down inside. After replacing the controller he dug the potting out, dried everything, reinstalled it and it worked again. Many owners have opted to revert back to the old tried & true wax valve. If you feel that is something you are interested in you can look to Source Engineering https://sourcerv.com/conversion IRCC Source owners were engineers at Monaco before the bankruptcy. They can answer many questions plus they make, sell & install other enhancements for Monacos. Edited February 9, 2023 by Ray Davis Link to comment Share on other sites More sharing options...
jacwjames Posted February 9, 2023 Share Posted February 9, 2023 Only thing I can think of is that the electric solenoid valve has something to do with pushing air through the radiators to help cooling at lower speeds possibly for the AC condenser? The thermovalve would normally lower the fan speed at idle and or lower temp but maybe with the solenoid valve it will speed it up. 1 Link to comment Share on other sites More sharing options...
dl_racing427 Posted February 11, 2023 Share Posted February 11, 2023 If the A/C condenser is sandwiched with the radiator stack, that could explain the presence of both. 1 Link to comment Share on other sites More sharing options...
Bill R Posted February 11, 2023 Share Posted February 11, 2023 (edited) Following this thread, and having a recent experience of repairing my WAO fan with the Sauer Danfoss (SD) controller, I ended up learning a lot. More than I had perhaps signed up for. Building on with @dl_racing427 and @jacwjames, and @Ivan K's Drawing, the solenoid could likely be on/off for when the AC is switched on at start-up and the engine water temp has not gotten warm enough to have the Thermo Wax valve start to close off and speed the fan up to provide enough cooling for the condenser. A way to test is to buy a tachometer, fairly inexpensive, and check your fan speeds on start up and see if the fan speed changes when you turn on the AC. If yes, then that is what the solenoid is doing. Or I guess you could also just measure the voltage to the solenoid and see if it changes when you turn off/on the AC. If it is not the AC switch that changes the voltage, then I am stumped like you are. Typically if you have the SD Controller, you do not have a Thermo Wax Valve. Unless it was added afterwards like @vito.a mentions. But yours seems original, so it is highly unlikely that you have the SD controller. Hope you get it figured out Charles. Edited February 11, 2023 by Bill R Link to comment Share on other sites More sharing options...
Ivan K Posted February 11, 2023 Share Posted February 11, 2023 Charles, I just noticed a relay in Left rear run bay marked ' Hydraulic Fan', could be what keeps your fan blasting, if you also have that? Link to comment Share on other sites More sharing options...
Flyinhy Posted February 11, 2023 Author Share Posted February 11, 2023 Ivan that was the first thing I checked and changed. I also bought a new intake temp sensor just to eliminate that. I think you guys are right about the a/c. Without a computer and Insite, I can't check the parameters of each function as described in your previous post. I will go home this weekend and bring back my a/c gauges and 134 bottle. That way I can make sure my high pressure is correct and not triggering that ECM function. Just one step at a time. Thanks for all the input from you guys...... Link to comment Share on other sites More sharing options...
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