FDCA Fan Controller Availability

[Malewis11]

On 4/10/2024 at 8:35 PM, robertmrankin6612 said:

Hi Guys,

Well my pursuit has stalled for a bit until I can figure out how to get the plug out of the valve body.  I have tried both pulling and twisting the round plug, but it doesn't seem to want to move.  I don't want to lean TOO HARD on it as it is still currently working and I don't want to bust something.

Does this plug have a history of being stuck as well as a history of being corroded like Mark's?

I'm feeling a little stupid here, does the plug pull out, or does it twist?  Would you ever put a tool on it?

Learning

bob

Hi Bob

There is a Phillips screw in the center of the plug that connects to the valve body. If you remove that screw, the plug should come off easily. That’s when I discovered there was a lot of corrosion on the plug. Use a small screwdriver to pry off the plate on the connector to expose the terminals. My wires were almost completely disintegrated, but it was easy to determine which terminals the two wires were connected to. One was connected to the ground and the other one to the number one terminal. The other two looked brand new.   

The plug is exposed to moisture and is not water tight. Mine was oriented so that any water that entered the plug would be trapped. I rotated the plate 90° so that the wire entrance would point down. I do not plan to seal the wire entry so that if any moisture enters the plug it will be able to drain out, hopefully. Below is the plug that I purchased from Amazon.

Best of Luck

Mark

Edited April 12 by Malewis11

[robertmrankin6612]

AAAAHHHHhhhhhhhhhhh......got it Mark,

Thanks so much for the detailed explanation!!!

Now I can collect the stuff to make my test.  

I'll report back with the results.  It will be awhile, as my FDC is working, but the conversion is now on my to-do list.  IF it works as expected, I'm going to use my offshore boat procedure and leave the new part in service and keep the working old one as backup.

cheers

Bob

[robertmrankin6612]

OK guys, looking at this again, I'm thinking that this is a 2 speed fan option, not a variable fan speed like OEM (IF OEM is variable).

It seems to me that using the pwm motor controller sets the minimum speed, but the thermo valve set the max speed.

I was hoping the pwm motor controller would output variable voltage with a variable voltage input, but I don't think it does.  Also, the controller cited above has a minimum input voltage of 7 volts.  So even if the controller could output variable voltage with variable input voltage, it would only do so down to 7 volts input, and I think it takes zero volts to run the fan wide open.  Maybe when the input voltage drops below the specified 7 volts the controller shuts down and the output voltage goes to zero anyway.

Does my thinking sound correct?

Thanks, Bob

[Malewis11]

Hi All

First I can report that after cleaning the connector contacts and replacing the Hirschmann plug my fan ran a lot slower at startup. Not sure of the speed but it wasn’t roaring like usual. We will have to see if it speeds up at high temps but had to cancel my short trip because of an issue with my brand new tow bar. 
Im not an electrical engineer but my understanding of the PWM is that it doesn’t modulate the outgoing voltage but switches the power on and off known as the duty cycle. It lowers the average voltage thereby reducing motor speed. 12 volts at 50% duty cycle would mimic 6 volts. It stands to reason that if the supply voltage dropped to 8 volts the output would be mimic 4 volts if the PWM setting didn’t change although I not sure if it’s linear.

You can measure the output voltage but it has to be tested under load otherwise you will not see the voltage drop. This is based on motors so how valves like ours react may be different but based on other’s experience it obviously has some effect. Since I didn’t install the PWM I’m planing on setting up an experiment to vary voltage and load to see what happens. I’ll report any thing I learn. 
 

Mark L

[Bill R]

On 4/13/2024 at 12:30 PM, robertmrankin6612 said:

OK guys, looking at this again, I'm thinking that this is a 2 speed fan option, not a variable fan speed like OEM (IF OEM is variable).

It seems to me that using the pwm motor controller sets the minimum speed, but the thermo valve set the max speed.

I was hoping the pwm motor controller would output variable voltage with a variable voltage input, but I don't think it does.  Also, the controller cited above has a minimum input voltage of 7 volts.  So even if the controller could output variable voltage with variable input voltage, it would only do so down to 7 volts input, and I think it takes zero volts to run the fan wide open.  Maybe when the input voltage drops below the specified 7 volts the controller shuts down and the output voltage goes to zero anyway.

Does my thinking sound correct?

Thanks, Bob

Bob - if your input to the PWM Motor Controller is a constant 12V signal then yes, in a sense it becomes a two speed control.  However, as the RPM's increase on the engine, the fan will speed up along with the RPM's.  So it is a pseudo two speed with some variable speed based on the engine RPM.  This is why I have the ECM input going to the PWM Motor Controller.  The operation then becomes a variable voltage from the ECM based on Air Intake Temp, and Engine Temp to the ECM.

 

On 4/14/2024 at 4:21 PM, Malewis11 said:

Hi All

First I can report that after cleaning the connector contacts and replacing the Hirschmann plug my fan ran a lot slower at startup. Not sure of the speed but it wasn’t roaring like usual. We will have to see if it speeds up at high temps but had to cancel my short trip because of an issue with my brand new tow bar. 
Im not an electrical engineer but my understanding of the PWM is that it doesn’t modulate the outgoing voltage but switches the power on and off known as the duty cycle. It lowers the average voltage thereby reducing motor speed. 12 volts at 50% duty cycle would mimic 6 volts. It stands to reason that if the supply voltage dropped to 8 volts the output would be mimic 4 volts if the PWM setting didn’t change although I not sure if it’s linear.

You can measure the output voltage but it has to be tested under load otherwise you will not see the voltage drop. This is based on motors so how valves like ours react may be different but based on other’s experience it obviously has some effect. Since I didn’t install the PWM I’m planing on setting up an experiment to vary voltage and load to see what happens. I’ll report any thing I learn. 
 

Mark L

Mark - You have the basics down correctly.  Using a VOM and Tachometer, you can track the voltage (in and out) of the Motor Controller and the resulting fan speed operation.  These are the tools I used to fine tune the Motor Controller for my coach.  Let us know how it turns out.

[robertmrankin6612]

Thanks Bill and Mark,

I played with my 7-70 V. motor controller this morning.  And while I didn't have a motor connected while making my measurements, I think I may have answered some of my questions anyway.

First I connected the controller to 12V and was able to measure the output at around 12V., based on the adjustment knob.  Then I dropped the input to 7.5V., and was able to measure the output at around 7.5V.  Then I dropped the input to 6.5V.,  and measured the output at basically 0V., lt would give max fan speed.

I THINK I remembered reading on the forum that the larger ISM or ISX ECM output 12V, 5V, and 0V. to give 3 fan speeds, so not strictly variable.

In my surfing around I saw some pwm motor controllers that operate down to 3V, so if the ECM does output down to 5V. (or lower before 0V.), that controller would yeild a more variable speed than the 7V. min. controller before full on.  Even if the ECM only outputs 5V. before dropping to 0V.,like the larger motors, I'd dtill get a little more variabialty before the fan went to full on at 0V.

I'm going to try to source one of the 3V. min. controllers and try that.

Cheers, Bob

 

 

[Bill R]

@robertmrankin6612  Bob - were you measuring your fan speed at each of the voltage outputs?  Or was it even connected to the pintle control valve?  I am asking because on my control valve, when voltage gets down to 7V the fan is already WAO.  So there would be no need to get a MC for a lower voltage.  But your operation may be slightly different.  The only way to find out is to hook it up to the control valve at 7V.

[robertmrankin6612]

Thanks Bill for the 7V. WAO fan speed info on your rig.

I did not have anything connected to the pwm controller's output, I was trying to see if the PWM controller's output would track the input voltage, and I have concluded that it does.

Your 7V. WAO fan speed has me completely rethinking this experiment, however.   

The evolution of fan cooled radiators has gone from direct engine driven fan, to totally variable fan speed based on input from the engine ECM,  presumably in search of better fuel mileage.  It seems that depending on the application and the year of manufacture,  our ISL's fans have had an on/off wax valve; an off, 2 speed on; and a fully variable fan, and there are probably others.  ALL these solutions will cool our motors if properly sized and installed.  I'm not sure exacdtly what my 05 Dynasty has, but it has the SD controller and I can watch the temps on the aladdin and can tell that my thermostat opens at 180, the fan goes to high at 202, and cuts back at 199, and can cycle quite often, or can stay WAO.

Now Happycarz,  Bill, and Mark have me diving down this rabbit hole 🙂 (Too curious a mind and too much time on my hands......?)  Given that happycarz's rig has direct input from the ECM to the pintal valve, that is kinda my goal, BUT I REALLY want to protect my ECM.  I wonder if I'm not really overthinking this and should just try putting a reverse blocking diode and a 1/2 amp fuse in the ECM line and connect it to the pintal valve.  I'll try a test to see if I can find the actual current on the ECM wires before I forge ahead...............

Sorry for the diatribe......

Cheers Bob

[Malewis11]

Hello,

I have attached some interesting information for the SD assembly regarding the output voltage and operational theory. It seems to confirm that the SD is looking for a PWM signal at a duty cycle from the ECM that is proportional to the engine cooling needs therefore the fan speed requirements. The SD is capable of additional thermistor and aux inputs but mine is limited to one ECM input. 

For me this is boiling down to what the actual function of the SD electronic module is. It appears that our rigs are not utilizing or needing the full functionality or multiple inputs of the SD electronic module. It probably does not use the ECM signal/voltage to drive the valve but Bill’s setup appears to show that it is capable of doing so. The SD’s is programmable, so it likely has the ability to adjust output based on aux inputs (overrides) as well as keep the fan running even when the ECM provides 12 volts, which is precisely what the aftermarket dc motor controller does. What ECM voltage says go WAO? This is possibly 0 or a variable loaded into the SD by Monaco long ago based on engine temps. Personally, I’d rather go WAO at 7 volt than overheat. I’d recommend as much electrical isolation for the ECM as possible.

If this is in fact accurate, there has been a lot of wasted money and time rebuilding and buying new SD controllers.  
 

Mark L

[robertmrankin6612]

THANK YOU MARK!!!!

GREAD INFO AND POST!!!

This is helping me greatly in figuring out what kinds of tests I'm goint to attempt.

Yet unanswered in my mind is how much current the ECM wire can provide and tolerate......more testing in my mind.

As a side note, perhaps the reason that Bill's rig goes to WAO at 7V. is because his 7-70V. pwm controller goes to zero when the input from the ECM drops below 7V.

Bob R.

 

[robertmrankin6612]

WELL, I made some tests today on my 05 Dynasty.

When cold and running at high idle, my ecm to FDCA wire carries virtually no current. The + &- carry about 0.9 amps.  However, the wires from the FDC to the pintal valve carry about 1.1 amps.  So the FDC looks like it is amplifying current from the + & - wires.

Since my ecm to FDCA wire carries no current I’m thinking it is not a good idea for me to use that wire to drive the pwm motor controller to provide the pcm to the valve.

We know Bill’s works that way, but I don’t know how much current my ecm wire can sustain.

So I guess for now I’m at an impasse without a temp sensor to set the fan to full.

bob