Hydraulic fan problem

[Darrel]

Side Radiator fan problem on my 2007 KSDP w/350 ISL Cummins & Spartan chassis

My side radiator fan and controller is manufactured by Casappa of Italy. It is designed to fail in "safe" mode ie - no 12V causes full speed operation. It is supposed be supplied with 12v from the Engine Control Module by monitoring:
1) Engine coolant temperature
2) Transmission fluid temperature
3) Air Conditioner in use.

The fan has operated at full speed continuously since new. This is a drag on power (my fuel economy is 6.2MPG) and I have tried to get it corrected.
First try - Newmar Dealer, "Your engine is a 350HP Cummins ISL. We always order the 400HP version because of their better fuel economy."
Second try - Spartan service, Service center said "After consulting the factory service rep, you don't need to change the fluid in the hydraulic system."
Third try - Cummins service - Mechanic spent an hour with his computor connected and looking at various places said "Your engine is working fine and no trouble codes found. No problem!"

Today I finally decided to try my own diagnosis:
Step 1 Cut the wiring harness labled "ISB,ISM,ISX Fan Clutch" and measured the supply voltage. It was 10.8volts at all times Ign off, Ign on, Engine running??? If I reconnected to the fan controller it immediately dropped back to 0volts.
Step 2 Disconnected the wires again and supplied 12volts to the fan controller with engine running. Fan immediately slowed with 12Volts applied and speeded when disconnected. Since this is proper fail safe operation the fan controller is working correctly.
Step 3 Grasping at straws now. Found another unused connector labled "HYD Fan Motor, Side RAD, Air SOL, ISQ Rear RAD" and measured voltages. The voltage readings were 0 volts under all conditions. NO HELP
Step 4 Go to the forum and ask for help from resident experts. Any aid will be greatly appreciated!

Have a nice day - Darrel

[Romeo]

First of all, I know nothing about it.... but, I'm someone to talk to pending someone that really knows something.

The next question I would ponder is "why 10.8 volts... what feeds that circuit?"
I would try to trace the circuit to something that is supplying the voltage. I would search for a wiring diagram. For the ones that aren't in my owner's manual. I have contacted Spartan and they have emailed me the diagrams that I needed.

Next, I would try to figure out why the second circuit had no voltage, and go through the same process to locate the source to see if maybe the circuit was'nt activated and just needed a fuse inserted.

Next, I would run to the IRV2 forum and yell for help...

Hang in there, real help should be here any minute...

[Darrel]

Well Romeo I have indeed pondered the 10.8 volt mystery. Could it be a wire with the insulation rubbing through to a 12 volt source? Who knows!! The wires dissapear into a wiring harness maze that would require major surgery to disect. Secondly, I don't even know where the ECM is located.
You indicate that the wiring is supplied by Spartan.? My Spartan documentation is long on chassis mfgr info and sadly lacking in any electrical information.

With high hopes I wait - Darrel

[siggyd]

Hi Darrel,
You have done a fine trouble-shooting job !
You have prooven that many electrical complains go into deaf ears,unless
you find a good technician that would listen.
As for the 10.8 volts that go down to 0 volt as soon as you connect to a load---that tells me it comes from a solid state switch or a lousy connection. Does the ECM have a direct solid state 12 volt output? ..or does the ECM turn on a relay?---I don't know.I have no schematics yet for my new DSDP with side radiator and the ISL 400.
An other question is: Was the ECM ever programmed for a
2 speed fan?
Siggy

[Romeo]

Originally Posted by Darrel

You indicate that the wiring is supplied by Spartan.? My Spartan documentation is long on chassis mfgr info and sadly lacking in any electrical information.l

Darrel,

You didn't comment on contacting Spartan. Are you aware that you can call Spartan direct, not a Spartan service facility, but the factory? They have a 800 number, 1-800-543-4277.

If you describe the circuits you are dealing with they can send you the wiring diagrams if they installed them. They can also answer the questions about where the various modules are located. That is for the ones that they install. Some items are located and installed by the coach mfg (Newmar). If Newmar supplied an item or located (mounted) it, then Newmar will send you the wiring diagram or block diagram.

I have access to a service manual for my 2000 DSDP, so have copies of most all my wiring diagrams. Those that I find missing, I call for a copy to complete my set. I have located many item locations that were not shown in any of my owners manuals. The diagrams have been very helpful in finding where circuits were connected, and what was hiding in those black modules located throughout the coach. I found that serveral turned out to be fuse boxes that I would not have opened had I not learned that they were fuse boxes.

[Darrel]

Update:
Called Spartan direct as Romeo suggested and found them to be very responsive and helpful. A novelty in this day and age!!! They promptly sent me a download for my unit that showed the wiring schematics and connector diagrams. (Did you know that Spartan labels each individual wire?)
I was able to find that my KSDP has the variable fan instead of the on/off version. I was able to check wire continuity most of the way. Still don't know where the ECM is hidden though??
Spartan also suggested that Cummins should be able to control the fan through their diagnostic computor hookup. That will be my next step, but in the interim I have connected the fan controller to the towed vehicle tail light circuit and I can control the fan manually to see the realtime effects.

Still fooling with this thing - Darrel

[Romeo]

"Still don't know where the ECM is hidden though??"

Did the Spartan diagrams show the ECM, indicating that it was supplied an located (installed) by Spartan?

If not it maybe located by Newmar and should show on a Newmar diagram. If this is the case, have you checked with Newmar.

So far I have found all those type of things with the Spartan and Newmar diagrams. I was just given a Newmar "Technical Service Manual" CD. It has quite a few Spartan and Newmar diagrams for all the Newmar models, but not 2007.

[Skip426]

Hi there, I have not worked on Cummins in a Motorhome application; but if the ECM is a cummins installed item, it may be bolted to the side of the block, on the intake side,as it is on 5.9/6.7 Dodge P/U applications.

[Perry White]

Take a look at this. It's an insite adjustable parameters for the fan on an ISL4E engine. If the AC is on it makes a fan switch that runs the fan all the time. Might be a problem. If I had the ECM # or Eng#sn I could look further.

[Perry White]

Here's the whole tree opened up. You can see all the adjustments you can make, like I said IF it's your motor. Did you say Cummins already looked at this?

[Perry White]

Look on page 46

[Darrel]

Perry - Thanks much for the INSITE information. When I took my MH to the shop for this condition The tech hooked up his computor and from then on wandered around the coach and gazed at various places while the engine was operating. I wasn't smart enough to ask pertinent questions. Now I think I'll go back and see if I can get some clarifications!! Also it appears that a faulty AC pressure switch is high probability failure condition.

I did finally have an oportunity to test the MH while operating the fan manually from a switch. Several trials on flat road conditions at 62MPH yielded:
Fan on - 6.2MPG instantaneous readings
Fan off - 7.2MPG instantaneous readings
That is an improvement of about 15%.

Still working on it - Darrel

[Skip426]

Darrel, I don't know if your still tracking, your fan problem, but I am still interested as I have my own issues, overheating , fan running at approx 20% . My system won't fail safe to full fan on. Bad control module according to F/L. Have to disconnect power at the valve to get full speed from fan.
Two notes, that may help if your still in trouble shooting mode.
#1 the RFC module in my coach works off a data link to the ECM, it is powered seperately, from a relay that is switched by the ignition.
#2 the relays in my coach all have resistors internally, and I can't find any one who can tell me why on this unit they are necessary. Speculation is that the resistors are for cars equiped with body computors to test circuitry, But I wonder if they are the cause of your 10.8 volt power feed.

[Darrel]

HoRay
My fan is working now. Armed with schematics (thanks to Spartan) I showed the tech the connections. Armed with the pertinent Insite documents I was able to get the tech to check the fan parameters.
Behold - - the fan was on top speed because the ECM thought the AC was operating. I had already checked the AC sensor and thought it was good. However after digging deeper, the sensor connector had an unseated pin that made intermittant contact. Reseated pin, problem fixed.
Bottom line - Engine temp runs about 10 to 15 degrees warmer and the fan is quiet. According to my calculations the 1MPG improvement will payback the service bill 4 times over in a year
Many thaks to the great bunch of iRV2 friends who helped me.

Have a nice day - Darrel