Problem wiring Linning two speed fan clutch

[benneu]

I am currently helping a friend with the installation of a S-60 engine and Allison World Transmission.  Both motor and tranny came out of an 1995 Provost.  We got the wiring diagram for this type of fan clutch from the Prevost CD and even checked with Prevost tech support.  Still, the fan is not working when using the Prevost wiring diagram.  The tech actually told us to switch one wire on the low speed fan, but it did not fix the problem  We are using wire # 555 for the low speed and wire # 563 for high.  At this time the fan comes on immediately after starting the engine.  We have been told that is wrong and the fan is not supposed to come on before reaching 204 degree.  Also, at 210 degrees, the high speed fan still did not come on. If any one could shed some light on this problem and really understands this installation, help would be very much appreciated.  The 563 wire I found was in a harness of three wires, 563, 564 and 565.  I found this engine harness a few inches above the right side of the ECM.  It had a dead plug installed and looked to me as if it was never used.  I wonder were else I can find wire #563.  It is not at the ECM.
Ben

[Hard Headed Ken]

You probably know this, but just in case. If your using the factory Prevost clutch it's 24 volt. Don't activate the fan directly with the ECM outputs, use relays. When the ECM turns on the outputs they go low (become grounds).

Ken

[benneu]

Thank you Ken.  The installation is into an Eagle Bus with 12V power.  We used a DC Converter to convert 12V  DC to 24V DC just for this two speed fan clutch.  The switching is done using 12V relays.
Ben

[Hard Headed Ken]

Ben,
I just got to my shop and I'm looking through the DDEC III / IV application / install manual.  Wire 555 is from the Vehicle side harness, 563,563,and 565 are outputs from the Engine harness side. In the repair manual 563, 4 and 5 are listed as sensor harness. All of these are called digital outputs in the A&I manual. That means the outputs are selectable using DRS (Detroit Reprogramming Software) and can be programed for different functions for different vehicle manufactures. That's why the A/I manual doesn't give their functions. Since the engine is from the bus it's most likely programmed correctly. The only way to know for sure is with the DRS software or maybe the harness diagram for that bus. If you have the VIN for the original bus you should be able to get the diagram on Prevost's website. I looked in another DDEC ECM program I have from a Prevost about the same year as yours. It has the low speed switching on at 195 F and on high at 203 F.

Are you able to activate the fan by manually grounding the relay coils?

Ken

[benneu]

Thank you Ken.  Yes, when I ground the relays high and low will come on.  The problem is, that I am not getting a signal from wire 555 or 563.  I wonder if it is time to go to Detroit and have the ECM tested and have them give me a print out of all wires and their function.
Ben

[stevet903]

Do you have the serial number of the bus that the engine came out of?  I was looking at the wiring diagrams online, and it looks like the early 1995 buses did not use the outputs from the ECM for the fan clutch.  The diagram shows a 3 pin water temperature sender (doesn't say, but probably on the engine) with one pin going to +24V on a 16 gauge wire 24-290.  The other two wires are 16 gauge and labeled 24-291 and 24-292 which go to the low and high speed on the fan clutch.
This is on wiring diagram D060815 rev 95-03-15  Later revisions show the fan clutch using the DDEC outputs. 
Steve

[luvrbus]

Most of those have been re programed to work off the ECM the sensor for the fan wasn't a good idea,Ben I thought you were home taking care of the orchards lol it's getting hot in Yuma George will probably leave fan or no fan

good luck

[benneu]

Steve, thank you for your reply.  I think you are right.  I ask myself several times: why did the engine harness plug have a dead plug in it.  We only have a partial Vin # of the bus.  Apparently it got burned and only a portion was readable.  I would appreciate if you could guide me to find the drawings you are talking about on the internet.  I sure would like to look at them.
Ben

[benneu]

Clifford, I got back from Yuma about three weeks ago.  I had to go home before we were able to test the bus because George still had to finish a few mechanical problems with the install.  I am talking to him daily and trying to figure out some of the problems he is still having.  One of them is the Linning fan clutch.  Also his cruise is no working.  I was looking at the print out from Detroit Diesel and it shows his VSS Signal to be "Switched".  At my S-60 the signal is magnetic.  I wonder if that is the reason the cruise is not working. It was 107* when I left.  George was reporting temperatures between 112 and115*last week.
Ben

[Boomer]

Silly question Ben, but I presume George has a ProLink and has enabled cruise?  Also, is the vehicle VIN in the ECM data?  Not sure about DDEC III.  I hope George is taking it easy in that heat and not getting too stressed out.

[stevet903]

Prevost's wiring diagram web site is frustrating to use, so here goes...
To get to the main menu, go here:

http://prevostparts.volvo.com/technicalpublications/en/wiring.asp

I chose vehicle type as an XL-40 and year of 1995, then click search.

A panel of results comes up -in this case it comes up with one result - D060811 - and click on it.
A new panel of results comes up - I pick the last result because that should incorporate all of the changes for the 1995 model year.
In this case I click on the last item, the 7/15/1995 Update. It brings up a new panel of results - pick the FAN-CLUTCH RADIATOR
and you should finally get the wiring diagram you are looking for.

Steve

[benneu]

Thank you Mark.  No, George does not have a Pro-Link, but he took the ECM to Williams  Detroit Diesel In Phoenix and got a printout of his engine calibration and it shows VSS enabled, cruise enabled, cruise auto resume disabled, cruise VSG disabled and cruise engine brake enabled.  Also it shows VSS Type to be tail and VSS Signal as "switched". His ECM had the 30 pin connector witch supplies all the end users DDEC feature's like Cruise and Jake removed for some time and it showed corrosion.  George cleaned and inspected all the pins of the ECM but so far with no success.
Ben

[benneu]

Mark, I just noticed I only answered part of your question.  The Pro-Link for DDEC ||| will not give you the ViIN ", only the model and serial # of the Detroit Motor and the serial # of the ECM.
Ben

[Boomer]

Wasn't sure on the DDECIII Ben, I only had IV and V and you could enter info like unit number and VIN via the DDC Diagnostic Link software.  Try checking with Eric Brown on the Eagle board, he had a ton of trouble getting his cruise and other configurations figured out, but he did and might have some valuable info.

[benneu]

George has been talking to him.  Apparently he had a bad ground on the brake switch (953 wire)
Ben