Hayden Fan Electrical Circuit on 2000 LXi

[cmillsap]

First, be aware that this only pertains to a 2000 LXi (as far as I know) Some other model Wanderlodges may have the same Hayden Fan electrical circuit as the 2000 LXi but I don't know if they do or not.
I do know that the Hayden Fan electrical circuit was changed and improved sometime after the 2000 LXi model.

The Haden fans (2) attached to the Hayden radiator on my LXi are controlled through a control circuit from the ECM through a 160*F N.O. single probe aquastat located on the bottom of the hydraulic oil reservoir. That control circuit energizes & de-energizes the Hayden fan's relay based on the opening and closing of the aquastat.

During the process of upgrading my PTO to a 1" wet spline, while we were draining the hydraulic oil out of the reservoir; we noticed that the aquastat looked to be in poor condition, so we decided to change it in the process. Once the new aquastat was installed we wanted to test it by jumping its N.O. contacts to assure the rest of the circuit components were working properly and the Hayden oil cooler fans were being controlled.

Alas! Neither fan came on! On inspection; we found one of the two fans was seized. Further inspection of the circuit found the 30A fuse in the rear panel blown. Obviously, what had happened was that the one fan seized drawing an overload and blew the 30A fuse. Both fans are wired through that one 30A fuse, so neither fan was working.

The reason I am posting this is to make 2000 LXi and maybe other model Wanderlodge owners aware. We have not been able to see any way anyone would know that their Hayden Oil Cooler is not operating properly. There is no warning light or buzzer ( that I am aware of) to tell you that your Hayden fans are not operating properly allowing the hydraulic oil temperature to overheat. The electrical schematics are void of any warning circuit that we can find.

Subsequent updates to the Hayden circuit was done as evidenced by a schematic that David sent me for his 2002 LXI. That Hayden Fan Control circuit included the following upgrades. The single probe aquastst was upgraded to a double probe unit. One probe controls the circuit to the Hayden fan at 160*f. The other probe is wired to a warning light on the dash and illuminates it if the oil temperature reaches 200*f. Also, the two fans were given individual circuits after the relay and ran through two seperate resetable breakers. A big improvement, needless to say.

Unless someone can enlighten me, it appears that 2000 LXi owners presently have no way of knowing whether their Hayden cooler is working properly or NOT.

[davidbrady]

Hi Chuck,

Thanks for the write-up - that's great info.

Short of wiring in another fluid temperature probe or an LED 'Fan On' indicator in the Hayden fan circuitry (which may eventually be a good idea), we can learn a lot by simply observing the hydraulic fluid.

Here's a fascinating link I ran across that talks about hydraulic fluid testing, typical test results, and fluid color and smell.

The idea of monitoring fluid color, smell, and levels is also probably the best way of determining general seal failure. We have many places in our drive-trains where one fluid is separated from another by a single seal: hydraulic steering pumps on our Series-60 separating hydraulic fluid from engine oil; coolant pump on our Series-60 separating coolant from our engine oil; Series-60 oil cooler bathed in engine coolant; transmission cooler bathed and enclosed in radiator top tank; and PTO and fan pump wet spline kit separating transmission fluid from hydraulic fluid.

In many of these cases an early indicator of issues would be tainted fluid; that is, unusual fluid levels, smells, and colors.

Periodic fluid testing is also a very good idea - if only I could be so disciplined.

[timetravelers]

Slim Somerville showed me a very quick and easy check on the Hayden fans-- with the bus at rest, nothing on or running, take a screwdriver and short the two temperature probe terminals. If the fans or fan comes on, you either have one or two fans working. If, in my case, no fan comes on, it's time to replace both fans. My fans were corroded with the motor shafts seized.

I definitely think the upgrade on David's coach is worth installing. What is the source and part number of the dual probe?
(Indulge me Chuck for restating your post in a little different way.)

[davidbrady]

Morey,

Three years ago I bought a hydraulic reservoir thermo sensor with alarm from Holland Motors Michigan. I gave them BB part number: 0012070.

If Holland is no longer helpful we can get it from Index Sensors. I attached their catalog and as best I can tell it would be part number 8036201 on page 16. The thread is 1/2" NPT. The temperature setpoints on mine are 160 deg F to turn on the fans and 200 deg F to illuminate the LED on the dashboard. Testing of this device is a little different than your usual Alarmstat. Page 170-5 of the 2003 LTC-40 Service Manual explains the procedure.

We have diagrams of our Hayden components including the fans here in our Document Library.


  Index Sensors.pdf (Size: 1.48 MB / Downloads: 5358)

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(07-12-2013 22:55)cmillsap Wrote:  The Haden fans (2) attached to the Hayden radiator on my LXi are controlled through a control circuit from the ECM through a 160*F N.O. single probe aquastat located on the bottom of the hydraulic oil reservoir.

Hi Chuck,

I'm not aware of any Detroit Diesel ECM output that would control the Hayden fan circuitry. It could very well be that this is the case on the 2000. I know that on my 2002 there's no ECM involvement. This might be another step in the upgrade.

[cmillsap]

David,

I am a poor reader of electrical schematics. The electrical technician at Redlands is very knowlegeable. We used the D.W.Frame Comp # 0000633M Page 6 which shows the control circuit source comes from the ECM IGN. I didn't follow that circuit further to determine its origination. I should have been more specific in my original post.

BTW, that 30A fuse we found in the rear panel does not show on the schematic. It is wired between the relay contacts and the Fans on my bus.

[patticake]

What circuit are ya'll talking about? The one that controls the radiator fan and the power steering?
If so, does that mean ya'll have a cooler in that system?

[cmillsap]

(07-13-2013 12:34)patticake Wrote:  What circuit are ya'll talking about? The one that controls the radiator fan and the power steering?
If so, does that mean ya'll have a cooler in that system?

Beside the engine radiator sits a smaller Hayden Oil Cooler Radiator. It is equipped with 2 electrical powered fans. The purpose of this radiator is to cool the hydraulic oil used to run the hydraulic motor on the big engine cooling fan. IOW, the hydraulic oil in the blue tank

[davidbrady]

(07-13-2013 11:51)cmillsap Wrote:  David,

I am a poor reader of electrical schematics. The electrical technician at Redlands is very knowlegeable. We used the D.W.Frame Comp # 0000633M Page 6 which shows the control circuit source comes from the ECM IGN. I didn't follow that circuit further to determine its origination. I should have been more specific in my original post.

BTW, that 30A fuse we found in the rear panel does not show on the schematic. It is wired between the relay contacts and the Fans on my bus.

I just checked my bus. I was correct the thermal sensor with alarm that I have is an Index Sensors component - part number 8036201.

Maybe Pete will chime in here, but I seem to recall him explaining some time ago about an BB engineering change to the Hayden fan circuitry. Something about the Haydens originally fused with a 15 amp fuse that kept blowing shutting down both fans. It was in the fuse block at the engine compartment and labled "aux fan". BB rewired it to a separate fuse holder and made it 30 amps.

[cmillsap]

(07-13-2013 18:23)davidmbrady Wrote:  

(07-13-2013 11:51)cmillsap Wrote:  David,

I am a poor reader of electrical schematics. The electrical technician at Redlands is very knowlegeable. We used the D.W.Frame Comp # 0000633M Page 6 which shows the control circuit source comes from the ECM IGN. I didn't follow that circuit further to determine its origination. I should have been more specific in my original post.

BTW, that 30A fuse we found in the rear panel does not show on the schematic. It is wired between the relay contacts and the Fans on my bus.

I just checked my bus. I was correct the thermal sensor with alarm that I have is an Index Sensors component - part number 8036201.

Maybe Pete will chime in here, but I seem to recall him explaining some time ago about an BB engineering change to the Hayden fan circuitry. Something about the Haydens originally fused with a 15 amp fuse that kept blowing shutting down both fans. It was in the fuse block at the engine compartment and labled "aux fan". BB rewired it to a separate fuse holder and made it 30 amps.

Yep, it is an inline 30A fuse holder on the wire between the fuse block and the panel wire collar.

[patticake]

Now that is a good idea. Wish I could do that on mine. Now another thought, On some of my old cars, I use electric fans, but wire them with a relay and a fuse. Just making sure it gets full current. Think of it this way, how long is the run from the fuse block to the fan. How much current are you losing. Those fans draw some juice. Just a thought.