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Variable Speed (4 speed) Cooling Fan Controller Project

Is the resistor going to be mounted in the fan shroud/airstream? I don't know if there are wattage ratings for these kind of resistors, but you're going to be putting a lot more heat into it than the original application did.

I have a DCC running an aftermarket 16" fan on mine, but it doesn't draw nearly that much current. It took the guy about 6 weeks to send it out, with zero communication.
 
Interested in this project to see where it goes.
Dave, are you manually switching these?
I haved used 850 fan relays with a 940 turbo fan/radiator and controlled low speed with a 240 turbo sensor in the lower radiator hose and the high speed in the radiator tank. I ran this for 5 years without problems. The car had a 160* thermostat and stayed cool, even with 100*+ Georgia summers. I upgraded to 120 amp alternator, so I never had any noticeable problems with fans. I was running the stock a/c fan which ran continuosly without problems. This was in 740 16V.
I grabbed some extra relays and sensors just in case of failure, but never had a problem.
 
DET17 said:
Dave, another option for those not wanting to "roll their own". I've run a simple Painless E-fan controller in my Chevelle for about 10 years now without issue. Here are their higher tech current offerings:

http://www.painlessperformance.com/webcatalog/fan5

Looks like some of these will handle extremely high amperage fans.
Click to expand...

Looks decent. Too bad they don't offer a radiator fin probe. I prefer to not have to have a new sensor port welded into my nice big aluminum radiator every time I change brands of fan controllers. And I really don't want 100% as the only AC option. I think not needed for a Mark VIII fan. I have it set to run at 77% for AC now. I think that will work. I appreciate the suggestion though.

Anyone used the Derale? Haven't heard about that yet. I know they have a high amp version with radiator probe.
Dave B.
 
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wennstroma said:
Is the resistor going to be mounted in the fan shroud/airstream? I don't know if there are wattage ratings for these kind of resistors, but you're going to be putting a lot more heat into it than the original application did.
Click to expand...

Yes, in the lower left corner of the shroud.
I tested the car for about 45 minutes this morning at idle, fan was running at low speed during the test. I registered temps up to 140 degF on the low speed terminal. Keep in mind that was probably about the ambient temp of the shroud.
Dave B.
resistorinshroud.jpg

4spcontroller3lo.jpg
 
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MikeSr. said:
Interested in this project to see where it goes.
Dave, are you manually switching these?
I haved used 850 fan relays with a 940 turbo fan/radiator and controlled low speed with a 240 turbo sensor in the lower radiator hose and the high speed in the radiator tank. I ran this for 5 years without problems. The car had a 160* thermostat and stayed cool, even with 100*+ Georgia summers. I upgraded to 120 amp alternator, so I never had any noticeable problems with fans. I was running the stock a/c fan which ran continuosly without problems. This was in 740 16V.
I grabbed some extra relays and sensors just in case of failure, but never had a problem.
Click to expand...

Switching is done by Hayden adjustable sensors for Low, Medium and High. Look at Posts #2 and #10.
Here it is done and installed. I opted for a fancy looking Hella relay box, suggested by Texas240.
Dave B.

4spcontroller1lo.jpg

4spcontroller2lo.jpg
 
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dbarton said:
I began this thread yesterday. Still testing. Will be on the road soon. I guess all the true turbobrickers have left. All we have left are naysayers.

Dave B.
Click to expand...

Dave you know me better than this. I am interested in knowing your results but I have also tried this idea before but using a different resistor setup. Mine failed but I sure hope yours works.. Your execution is flawless tho.

Keep us posted I hope this works.


-Sam
been turbo bricking since way back..
 
Took a nice trip for about 50 miles on highways, traffic and 80 mph freeway. With AC and without AC flawless so far. Next I think I'll add a small LED near my override toggle that will glow when the fan is on.

Dave B.
 
Mueller said:
How much $ do you have invested so far?
Click to expand...

Including the high-dollar ($48) Hella relay box, prolly about $200.
I paid $57 for three Hayden temp sensors.
$6 for the ABS box for the sensors.
$8 for the resistor board.
$8 for the maxi fuse holder.
and whatever for relays, wire, terminals, heatshrink, most of which I had on hand.

Dave B.
 
dbarton said:
A ceramic ballast resistor? I briefly thought about those. Don't know. Never played with one before to regulate a fan. Seems like it would take a lot of space for the same multi speed effect.
Dave B.
Click to expand...

Yes, the ceramic are the type I meant. Those blower resistor packs tend to suffer element corrosion, and they fail to an open circuit condition. Maybe in the mounting location you've chosen and in your climate, yours won't suffer the fate I have often seen. At least if it does it's a cheap part to replace. Very tidy work in your photos, I like it a lot.

As far as the ceramic ballasts' size, the bmw parts I have in mind (and possess) are around 15mm x 60mm. I'm considering just a 2-speed triggered by a single 3 terminal temp switch in the rad. I've been running just full speed with my Derale fan for a couple of years, and it's a bit noisy but never runs when traveling faster than 25mph or for more than a minute or so below that driving speed. A slightly quieter fan speed under 25mph may be plenty quiet for me.
 
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brian smith said:
Yes, the ceramic are the type I meant. As far as the ceramic ballasts' size, the bmw parts I have in mind (and possess) are around 15mm x 60mm.
Click to expand...

Google found me the below pic. Can they be found in different ohm values so predictable speeds can be done?
Cost seems to be a bit high at $20-something each.

So to duplicate what I've done using ballast resistors, you would need three. A 0.3 ohm, 0.8 ohm, and 1.6 ohm (or close to those). Can they be found?
Dave B.

a20792913d28e02e5c8b11_m__33785.1417458994.500.659.JPG
 
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dbarton said:
I appreciate the comments. More are welcome.

If you think this is stupid, tell me.

Thanks, Dave B.
Click to expand...

Not stupid! Clearly, you've chose to roll your own out of frustration with all the previous controllers. Looks like shooting rabbits with a bazooka (to me), but I've not lived your frustrations. One last thought and I'm out..... have you looked into what the Buick 3.8L Grand Sport guys do for cooling control? They make stupid power, and you know that Buick cooling system must be getting hammered with similar (or greater) transient heat loads.

And I thought you were still singing the praises of the "Tropical Fan" :lol: Good luck, Dave.
 
DET17 said:
Not stupid! Clearly, you've chose to roll your own out of frustration with all the previous controllers. Looks like shooting rabbits with a bazooka (to me), but I've not lived your frustrations. One last thought and I'm out..... have you looked into what the Buick 3.8L Grand Sport guys do for cooling control? They make stupid power, and you know that Buick cooling system must be getting hammered with similar (or greater) transient heat loads.

And I thought you were still singing the praises of the "Tropical Fan" :lol: Good luck, Dave.
Click to expand...

No. Haven't noticed what they're doing. I'll browse around.

I still like the tropical fan for stock configuration. It surpasses almost everything except my Mark VIII. I've gone past the point of no return though?
Dave B.

lincolnmark8fan2.jpg
 
DET17 said:
have you looked into what the Buick 3.8L Grand Sport guys do for cooling control? They make stupid power, and you know that Buick cooling system must be getting hammered with similar (or greater) transient heat loads.
Click to expand...

This is what I'm finding for GNX people. They're using some wide radiators to fit dual fans. Nice. Expensive. Prolly 4 times the money I have in mine.
DSC00730%20small.jpg


EDIT: No wait. Those are only 12 inch Spals that put out 1390 CFM each. Sorry, but my Lincoln fan kills that.
 
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dbarton said:
Here are revised fan amperage figures at higher voltages (with engine idling). The fan pulls a lot out of the alternator, so testing at 14.4v will not be possible. And it sounds like a jet engine at 40A :-D.<snip>

Resistor Pinout . . . .Fan Percent . . . . Amps Constant/@Voltage/Watts
Fan full power . . . . . . 100% . . . . . . . . 40/13.3v/530
1. High . . . . . . . . . . . 77% . . . . . . . . 29/13.6v/395
2. Medium 2 . . . . . . . . 55% . . . . . . . . 15.7/13.9v/217
3. Medium 1 . . . . . . . . 36% . . . . . . . . 8.6/14v/121
Click to expand...
LOL, awesome. Try redline for more current! ;-)

I was thinking about trying to calculate the theoretical value for 14.4 but I'm not sure there's enough data there. The figures are totals, presumably. You'd need to take a centre tap and measure the voltage across the fan only at the same time as the current, then you'd get a curve that could be interesting/useful :-)
 
dbarton said:
I began this thread yesterday. Still testing. Will be on the road soon. I guess all the true turbobrickers have left. All we have left are naysayers.

Dave B.
Click to expand...

Dave, not all have left. :cool:

There is not a single post or thread you have ever made over the many years we have been on this board that has not been considered valuable by me. I read all of your contributions and follow all of what you do, and thats a fact.:) I first got the fuel pump relay mod from you back in the day and never looked back. :-D. But, yeah, the audience and the board demographics have changed for sure...:oogle:

Following this with high interest.
 
Thank you.

I've created a page within my website dedicated to this project. I'll post new content there. I'm pretty confident that the design will continue to work well and that the relay board won't be melting any time soon. I went through several design versions, additions, deletions before I began posting in TB. My reason for posting here wasn't to get a few nice strokes, but I hoped it might help improve the final design or find useful critiques. TB used to be really good for that. Not so much the last 5 or 8 years. That kind of decline really suppresses the kind of growth this hobby needs to survive. But I guess everything has its life/death cycle.

I'm still curious about the ballast resistor idea, since that could be a serious alternative, but excessive searches have NOT found much in the way of various resistance values to choose from. I guess I was hoping there might be a manufacturer of ballast resistors that were close to the values needed. Maybe it doesn't exist outside of mismatched ones from different places.

Dave B.
 
I like the concept of this, but was wondering why you chose to use 3 temp probes? Why not just use 1 coolant temp sensor and a micro controller like an arduino? The code would be simple to do and I know they can trigger relays. Just curious. By the way, I go to your website a lot , it has really good info. Keep it up!
Jeremy
 
Relay diagram

Aren't the low and high speed relays in your diagram misplaced? How is the low speed energized if the high and medium speed sensors have not triggered a ground yet when the low speed threshold is reached?
 
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