How should my fan clutch on a Series 60 work?

[belfert]

This is a spin off of Richard's thread about the fan on his Series 60.

I have a Series 60 with a belt drive fan.  It does have an electric clutch.  No idea if single or dual speed.  The clutch locks up as soon as the key is turned on without the engine even running.  I assume this is not correct and something is broken somewhere.

Don Fairchild suggested I probably have a Horton clutch, but I have never found any name or numbers on the clutch anywhere.  This bus was made in Mexico, but most driveline parts are American.

[buswarrior]

My guess is that the clutch locks on ignition on, engine off, because some part of the control circuit is not satisfied by way of the engine not running and providing some sort of input.

If we follow the fail safe strategy of the fan clutch's "Normal" condition is to be on fully, only being cycled off by way of some action by other controls.

The air operated fan clutch on my Freightliner clicks on with ignition on, engine off, and then resumes its function once engine is on and air pressure is present, if that is of any assistance.

happy coaching!
buswarrior

[belfert]

I will look in my book to see if talks about the fan clutch.  If that fails I will call MCI on Monday. 

It makes sense that the fan clutch might lock until the engine is running and it gets a signal from the temp sensor.  Does the power from the fan clutch run through the DDEC III?

[belfert]

I talked to MCI this morning about my fan clutch.  The tech indicated it should not be locking up as soon as the key is on.  There is a relay controlled by the DDEC that might be bad.  I'll have to check it out when it warms up a bit.

[Don Fairchild]

Brian;

I did some research and most MCI's came with a standard single speed Horton fan clutch. Go on there web site and you should be able to find either a diagram or a contact # for them.

Hope this helps

Don

[belfert]

Thing is I don't actually own an MCI.  I own a Dina.  MCI sold the Dinas in the USA and also provides technical support and parts for them.

I'll check to see if I can find a manufacturer name on my clutch.  In the meantime I will look at the Horton website.

[belfert]

Interesting.  I actually found Dina bus listed on the Horton website, but only for model year 1998.  It does say the clutch is discontinued.  I'll have to call them.

[belfert]

What Horton has listed is an air clutch, not electric, so it isn't the right one.

[Busted Knuckle]

What Horton has listed is an air clutch, not electric, so it isn't the right one.

Brian,
Most all truck/bus fan clutches are air. Some are controlled by electric solenoids, but most all will use air to actually engage the fan. (not all as several of my older Setra's were strictly electric)

Our Dina also has the fan click sound when the switch is put on rear start. I have not tried it with someone turning the front key on while I listen at the rear. (& @ 18* outside it ain't happening today either! So if you'll remind me to check it out when it's warmer, I'll be happy to do so!)

Have you checked your manual for the diagram of how the fan is configured? It could be as simple as a relay hung up. (we don't have a manual for Don's and since it is his, I don't want to buy one, but may have to someday!)
  BK 

[belfert]

The only thing going to the fan clutch is a wire so I am fairly certain it isn't air.  I don't see anything that looks remotely like an air line.  I have pored over the wiring diagrams and so far I cannot find the circuit going to the fan clutch.

I talked to MCI and they said it could be a bad relay causing issues.  The bus cools fine, but I would like the clutch to work properly if it isn't now.

[JohnEd]

All these things seem to be designed to "fail" to the engaged position.  You need air to disengage as well as lectric to disengage.  Smart move for the engineers and they deserve all the credit they can get cause they so rarely deserve any.

Start that bad girl up and hit the throttle.....you can tell in a heart beat if that fan is engaged if you are looking in the engine compartment.

2 cents,

John

[luvrbus]

The most popular fan clutch on the market today is the 3 speed electromagnetic clutch and they do click on when the power is turn on.


good luck

[rv_safetyman]

Brian, I have had to get my Series 60 Application and Installation manual out in the last couple of days, so I thought I would look at the fan section.  It is a very detailed section that describes what the DDEC ECM can control in the way of a fan.  It lists about every kind of fan you can imagine, including air clutch, electrical clutch, two speed, etc.  It also lists a ton of parameters that can be set points for various fan actions.  All of that culminates in the possibility of using two of the digital outputs for control of the fan.

The DDEC ECM has the capability of "controlling" several digital output "channels".  These functions are defined by the customer based on the hardware they want to control.  Once the customer defines the algorithm it is programmed into the DDEC for that customer.  The control signals are sent to locations on the main terminal block and then connected by the OEM to their equipment.

Thus, you will not find any documentation in Series 60 literature for your fan control system.  That was all established by Dina and you will need to get their documentation.

Jim

[belfert]

I've been looking in the Dina wiring diagrams, but so far no luck.  I don't have any of the Series 60 manuals to look at.

Clifford's explanation that all electromechanical clutches will lock up when the key is on and engine off I guess explains that.  My engine is cooling just fine.  My only concern is if the fan clutch is really allowing disengaging when cooling is not necessary.

[Don Fairchild]

Brian;

Start the engine and with some on the throttle you at the back of the bus listen and see if the fan runs until the engine gets up to some rpm.

It may be set to come on at start up then Idle if it does not need cooling Just like a car will.

Don