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Topic: 2001 U320 Hydraulic Fan Functionality (Read 1543 times) previous topic - next topic

Re: 2001 U320 Hydraulic Fan Functionality

Reply #20 –
Quote from: dlkj07 –
Are the fans supposed to spin up instantly on a cold start? Or is there a delay or a minimum temp that needs to be reached before they fire up?

Really wish I could find a flow chart somewhere that explains the fan functionality from start up to shut down for the electronic controller setup.
I don't know the answer to your question but I think you would want them to be running even when engine it too cool so the CAC could be cooled down.

Re: 2001 U320 Hydraulic Fan Functionality

Reply #21 –
Quote from: turbojack –
I don't know the answer to your question but I think you would want them to be running even when engine it too cool so the CAC could be cooled down.

Yes, even when coolant doesn't require fan speed, there must be air flow over the CAC.

So, think of this is LOW-HIGH, not OFF-ON.

Re: 2001 U320 Hydraulic Fan Functionality

Reply #22 –
Quote from: wolfe10 –
Yes, even when coolant doesn't require fan speed, there must be air flow over the CAC.

So, think of this is LOW-HIGH, not OFF-ON.
Ok got it, just checked mine and it appears to be stuck on high. I only say that because when i disconnect the controller it doesn't seem to change speed...may need to purchase one of those tachometer devices to know for sure but it doesn't seem to get loud or blow more air when i disconnect.

There could also be the situation where I'm using the Napa sensor and not the Danfoss...but who knows.

Re: 2001 U320 Hydraulic Fan Functionality

Reply #23 –
Dylan, I do know to hear your cooling fans on high while your parked you need to have the high idle switch ON. Jim.

Re: 2001 U320 Hydraulic Fan Functionality

Reply #24 –
Quote from: fourdayoff –
Dylan, I do know to hear your cooling fans on high while your parked you need to have the high idle switch ON. Jim.
I did not know that...and of course, my high idle/cruise is not working right now 😡

Re: 2001 U320 Hydraulic Fan Functionality

Reply #25 –
So Dyran you too have a failed electronic controller. Fails to the fans running fast position. The wax valve has infinite rpm ranges, not hi and low. Just as required. I certainly can hear my fans ramp up at a low idle from the drivers seat with my added solenoid commanding max speed by shutting off sense control pressure. I run a standard thermostat and the hi temp wax valve. I also run my background fan speed so low that the fans just turn prior to warming up. This will cause hi IAT which I've rairly see and I either reduce power settings or manually ramp fans up. There is a adjustment inside the wax valve that can be set but the manufacturer recommends they do it. Wonder lodge and blue bird use a additional IAT sensor and solenoid to manage cold engine hi IAT Issue. I had given consideration to this but never needed to add. I actually have a needle valve inline to the solenoid if I desire higher background speed but haven used except to increase fan speed too just turning so as to keep warm oil in motors and not damage bearing from setting in one position. Needle valve was also my safety blanket to command fans to max speed to get home if I had a issue. Suspenders and belt mentality.
Scott

Re: 2001 U320 Hydraulic Fan Functionality

Reply #26 –
Quote from: dsd –
That is correct. I added a solenoid that closes every brake application and when the retarder is applied also manually as desired.  I can easily hear the fans ramp up or down drop from the drivers seat. If your electronic controller has failed I wouldn't spend money on replacement. I would change to the wax valve control system.
Hydraulic fan controller DIY
Scott
Please explain:"solenoid that closes every brake application and when the retarder is applied"
Where is the solenoid valve placed?

Thanks Tim

Re: 2001 U320 Hydraulic Fan Functionality

Reply #27 –
So the solenoid was added in the fans speed pressure reference line. Restriction in this line causes the fan speed to increase to max. No restriction causes the fans to actually stop turning. So with the increase of temperature the restriction in the valve closes and increases fan speed. Wax valve or electronic controller. The added solenoid was added for several purposes. Extra cooling, extra dynamic braking, and yes I can feel and hear the extra drag when engaged. A way to dump all the extra heat I normally ignore but like to be able to stop and sleep in the bedroom without cooking for a hour. I drop 25 degrees off the top of my engine and transmission temperature compared to my normal OTR temps. I have increased MY normal OTR temps to about 200 and in doing so burn less fuel for cooling.  I have a three position switch which is fan override OFF (this is basically what everyone has on there coach stock, fan override ON, and fan override in AUTO Fans go to hi speed during brake application and retarder use. Eventually I will add a time delay off switch to keep the fans running a additional time after they no longer are requested. Not needed  but would like. 
So driving down the road normally in AUTO. 30 minutes before shutdown I like to go to ON position to dump heat. Yes it costs more fuel but worth it to me.
Note, after I initially installed the wax valve is when I recognized how nice it was prior with fans on hi to sleep quickly, much cooler. Also saw much higher retarder temperature. So when we use our coach it may stay running across the states with minimal overnight stops. Huge difference.
Scott

Re: 2001 U320 Hydraulic Fan Functionality

Reply #28 –
Wanted to hit on this topic again...

Today I was fiddling with my fans again. Noticed that the connector leaving the controller was green with corrosion on the pins. I cleaned them up the best I could and started the process below:

To circle back to the discussion of testing the fans by unplugging the controller while idling...I thought a good test would be to start up engine, unplug controller and then see if I notice the fans change RPM. If they ramped up, then the thought was the controller is working...but then someone mentioned in this thread that the high idle needed to be on for the fans to kick up and it wasn't until today that I tested that out. (My cruise control/high idle is still not working 100% so testing anything on high idle is hit and miss)

...so what actually happened is when the high idle is on the fans are definitely at a higher RPM than when at normal idle RPM. Unplugging the controller did nothing at either RPM. So normal idle, fans on lower RPM, unplug controller, nothing changes. High idle, fans kick up, unplug controller, nothing changes.

Are my fans working correctly?

I keep hearing people say that they can hear their fans kick up to higher RPM while driving but I've never heard that, seems to be too much other noise for me. Maybe if the passenger window was open and I was in a tunnel maybe i would hear it?
Maybe my rig is running so awesome it never needs the fans to ramp up to full RPM because it run so cool. (I know, impossible)

I'm not against installing the Wax valve and abandoning the electric controller but don't want to if I don't have to...for now anyway, too many other projects.