Adjustable controller for Spall fans Dewitts kits
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Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Adjustable controller for Spall fans Dewitts kits
I am thinking about getting the Dewitts rad and fan kit but I would like to be able to adjust when the fans come on and shut off. Anyone have a controller that is adjustable for the Spal fans ? 
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I have had the PWM controller for a couple of years now. It ramps up the fan speed so they do not run at full speed until needed. It starts out at 50% and goes up as the temp goes up. You can set your own on/off settings. One word of caution they cannot be set to close. Say on at 190 and off at 180. If I remember it has to be a 15 to 20 degree difference. I had a little trouble at first because I was trying to set them to close. Some have had problems with this unit mine has been trouble free for a few years now.
Thread Starter
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
They quit selling the PWM because of all the problems now the sell the old system which is preset at 195 on and 175 off 
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I talked to Tom about the PWM and he said for some reason the Vettes have a problem with the PWM. Other cars not so much. I keep my fingers crossed that mine keeps working.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Twin 50 amp lighted toggle switches. If and When the gauge gets to 180 I strain against my 5 point belts to reach the the dash to hit one of the toggle switches. If and when it gets to 210 I strain to reach switch number 2.
For awhile I had one come on with ignition, but I couldn't ever get the motor to heat up. I have not turned on the second fan yet and it was 90 over the weekend. So I'm thinking about putting in the next smaller reducer washer. I think that I have the one inch and need a 7/8th to get some heat in it.
Le Mans Master
Joined: Jun 2007
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From: Crush your enemies, see them driven before you, and hear the lamentations of the women TX
Here's one I was looking at with programmable temps. Haven't used it, not even sure if it's suitable, but maybe worth a look.
http://www.dakotadigital.com/index.c...prod/prd43.htm
http://www.dakotadigital.com/index.c...prod/prd43.htm
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
This is a common request so I thought I would comment on it. I'm sure everyone has heard of the KISS rule? It really applies with fan controls. The programable, solid state controllers are really over kill for such a simple fuction. The idea sounds great at first but you really have to program the on and off about 20 degrees different for these to function correctly. You also should maintain a 180 stat to insure that you burn off any condensation in the crankcase. So if you set them to shut off at 180, and turn on at 200, why is that any different than the fixed 175/195 that we offer? It's not!
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
This is a common request so I thought I would comment on it. I'm sure everyone has heard of the KISS rule? It really applies with fan controls. The programable, solid state controllers are really over kill for such a simple fuction. The idea sounds great at first but you really have to program the on and off about 20 degrees different for these to function correctly. You also should maintain a 180 stat to insure that you burn off any condensation in the crankcase. So if you set them to shut off at 180, and turn on at 200, why is that any different than the fixed 175/195 that we offer? It's not!
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
And there you have it. This is what Tom told me last year also. If my controller goes bad I'm going back to a simple system. In the future if/when I go to fuel injection I'll have the computer turn the fans on and off. I'd stick with the simple system if I were to do it over again.
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Thread Starter
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
This is a common request so I thought I would comment on it. I'm sure everyone has heard of the KISS rule? It really applies with fan controls. The programable, solid state controllers are really over kill for such a simple fuction. The idea sounds great at first but you really have to program the on and off about 20 degrees different for these to function correctly. You also should maintain a 180 stat to insure that you burn off any condensation in the crankcase. So if you set them to shut off at 180, and turn on at 200, why is that any different than the fixed 175/195 that we offer? It's not!
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
Another reason I like the simple relay and switch system is that they work almost all the time, but when they don't, trouble shooting is very simple. That's not the case with the electronics. The electronic senders are an analog device, which means you check them with an ohm meter. The controller are solid state devices and you can't check them, so when something goes wrong you fix them by replacing parts. The relay and switch system is so simple. If something goes wrong, you can touch the switch wire to some ground and if the fans come on, then the switch is bad. If they don't, then the relay is bad. Real reliable and real simple.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
i have been through 2 different types of auto fan switches , and my mate another brand. i found them to be unreliable to the point that occassionally they didnt even come on at the set temp. i have gone to the good old trusty set up of an on/off switch low on my dash where the over-ride lights pop up button is. now when my car hits 190 i just flick it on . once i start cruising i turn it off. its not a daily driver and im the only one who drives it so thats the way i like it.i have fairly good cooling so i only have to turn it on when im at the lights for a long period.most lights im going again before the temp gets up.its not for everyone but if you like it simple and fail safe i recommend it.
Drifting
Joined: Nov 2002
Posts: 1,951
Likes: 1
From: Shore NJ
I just installed a set of Dual Spals with the 195/175 this past weekend on another members car. The fans run all the time once the car is warm. It runs at about 160 to 170 but the fans still run. I think we got a bad switch. A new one is coming this week.
I talked to Tom about the PWM and he said for some reason the Vettes have a problem with the PWM. Other cars not so much. I keep my fingers crossed that mine keeps working.
I talked to Tom about the PWM and he said for some reason the Vettes have a problem with the PWM. Other cars not so much. I keep my fingers crossed that mine keeps working.
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Thought I'd chime in here, Gordon and I installed my fan kit this past weekend, as he mentioned the fans don't shut off. We have checked everything, using an IR gun and the gauge , have a 160 high flow thermosat, bled the radiator in case there was an air pocket, still the fans don't shut off, I called Tom DeWitt but he was out of the office and his person was very helpfull and is sending me a new sensor, hope this is the problem and Tom can add some feedback to this problem on this post.....Thanks
Burning Brakes
Joined: Aug 2002
Posts: 1,146
Likes: 10
From: Scottsboro Alabama
I wired my dual spals independent of each other. One fan is controlled by a sensor located in the head, the other fan is controlled by a sensor located in the intake. If one fan and/or sensor was to malfunction, the other one would continue to operate.
Melting Slicks
Joined: Jun 2004
Posts: 2,077
Likes: 0
From: westmoreland N.H.
try this one www.dccontrol.com works slick as goose grease. my temp comes to 182 and stays put .
Last edited by fugawi; Jun 17, 2008 at 07:44 PM.
Safety Car
Joined: Mar 2005
Posts: 3,503
Likes: 2
From: Raleigh NC
try this one www.dccontrol.com works slick as goose grease. my temp comes to 182 and stays put .
A perfect controller.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
try this one www.dccontrol.com works slick as goose grease. my temp comes to 182 and stays put .
To bad the link does not work like goose poop.
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
try this one www.dccontrol.com works slick as goose grease. my temp comes to 182 and stays put .
Drifting
Joined: Nov 2002
Posts: 1,951
Likes: 1
From: Shore NJ
Thanks Tom for the reply, my fans don't run when the car is started, they start when the temperature gets to about 160, then the fans start and will not shut off, Gordon and I have checked everything that's why we think the only thing it could possibly be is the sensor....anything else we could of possibly missed, it's a simple system to trouble shoot....Thanks again
Thread Starter
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Is this the link for the controllers, if so which one do you guys have ?
http://www.dccontrol.com/fancontrol.htm
http://www.dccontrol.com/fancontrol.htm
Drifting
Joined: Nov 2002
Posts: 1,951
Likes: 1
From: Shore NJ
Thanks Tom for the reply, my fans don't run when the car is started, they start when the temperature gets to about 160, then the fans start and will not shut off, Gordon and I have checked everything that's why we think the only thing it could possibly be is the sensor....anything else we could of possibly missed, it's a simple system to trouble shoot....Thanks again