Best method for controlling an electric fan?

I put a 250 six in my 50 sedan and now I will need to run an electric cooling fan (pusher). I am going to run a 14" fam that"s rated at about 1800cfm. My question is what is the best way to control the fan? I've found two different types of controllers, the ones that have a sensor that screws into the head and the other is the probe type that goes between the fins in the radiator.
I am running a 165 t-stat and was planning on running the lowest temp on-off that I can get. Any suggestions? Thanks, Todd

 

Not being a smart *** , but I use a toggle swith on both my 28's ! Turn it on when needed .

 

That's another option. I ***ume you just watch the temp guage and go from there??? Todd

 

There are quite a few adjustable setting controllers that use the sending unit for your aftermarket electric temp gauge to sense the temp. While they are "non-traditional" they are really good products as most have built in low and high speed fan circuits. Check out SPAL (what I am using), Dakota Digital, ZIRGO. Some are under $100, cheaper than overheating because you turned on a little too late.

The correct setting is when the fan turns on just about the temp the thermostat opens, and back off about 10 degrees under the thermostat rated temp. If it opens too soon it will be a useless drag on your electrical system cooling cold water that is in you radiator instead of the hot water in the engine.


Marty McF.

 

Your gonna find that it only need to run when you are not moving or idleing. I got a toggle switch on my 54 and only turn the fan on when crawling along at less than 20 mph. for more than a couple of minutes. Even normal traffic light timing doesn't heat the motor.

Mine is a 235, but you should be just as efficient, or maybe even better being more modern.

I got a 180 t-stat and it sits on 180 all day long. I was in NC with it a couple of weeks ago and it was over 100 and the temp did run 190 on the highway. But I left the fan off anyway.

Frank

 

I used a painless 30103 electric fan wiring kit, it was a little pricey but havent had any issues in 10,000 miles. You can actually download their diagram and source and build your own kit for cheaper.

 

Hey Todd, I may be a little **** with my plan, but, the fan came with a sensor that is jb welded to the radiator. No doubt I could have done it another way , but, the guy at the Former Total Performance said it was the fan they used on the cars they built. Anyway, It came with a relay that I have up front behind the grill. I also has a toggle that you can use to turn on the fan at any time you wish. What I plan to do is use a double pole double throw with center off toggle switch that will allow the fan to run by the sensor on the radiator when in one position. When in the other position it will over ride the sensor and run as long as I want it to. In the center off position it will not run as highway travel should be one time where you don't need it running.
Dom

 

I used one with the probe and I didnt like it one bit. took it out and wired it to a toggle..... much better.

 

toooogle switch with a small light

 

I have mine wired through a toggle

 

One of the best methods I found was a sender from a Saab 900(1980-up).It screws into a T fitting that goes into the upper radiator hose.There are actually 2 electric fans on a Saab;one is the normal engine fan and the temp sensor is set at 95 degrees C(about 190 degrees F)and the other is for the a/c which is set for 110 degrees C(about 220 degrees F).The sensors have the same thread on them so either will work in the fitting.The fitting is cast aluminum and fits the same size hose as a mid 70's Ford upper radiator hose.I used one on my V-8 Pinto and it worked very well.Don't know the availability new now but there should be plenty of them in salvage yards now.
If you must use a toggle switch,wire it through a relay to avoid overheating the switch.

 

I had a derale and it had the probe through the rad, and a AC override, so the fan would kick on if the a/c was turned on, since I have a convert and no a/c I used that for a toggle o if the probe did not come on I ould overide with the toggle.

 

Right now on my truck i'm using a toggle as well..
BUT, i have mine wired through a relay instead of direct..Much less draw and easier on the switch.
I've run three car's this way and never had an issue. I've become one with my temp gauge
Like what's been mentioned, i only use the fan when i'm either moving slow or idling, on the open road it stay's right at the thermostat temp of 180..
I will be looking into something like what Dooley has though. Not so much for automatic on/off of the fan, but for the A/C over ride..I have air in the truck and although i have never missed turning it on for cooling, i know i will miss turning it on for the A/C.

Tony

 

Toggle switch for the younger set. Sensor for the gray hairs.$0.02

 

the probe in the radiator fins ****, i've used them and they're rarely accurate. on the '47 i used the temp sender and fan relay from hotronics, they're a quality made piece and a small local guy (i went to his house to get it).
http://www.hotronicsproducts.com/

btw i started getting grey hair in high school.

 

Thanks for all the feedback. For now I think I am going to wire it through a relay to a togle switch. I'm pretty **** about keeping an eye on my guages so I don't think I will let the temp get away from me by not turning the fan on. Todd

 

I second that. If I turn mine off I forget to turn it back on.

 

on my dual fan setup I have the lo speed relay fired off the ignition and the high speed relay fired by a/c or the 185 degree screw in sensor I have on hte manifold.

I never heard good things about the radiator fin sensors, fwiw

there's also one that attaches to the outside of the radiator hose, made by be-cool, and they make good stuff, so I'd reckon it works OK, I probably should have gotten that.

If i were 19 I'd probably run a toggle switch too LOL

 

on off switch on when running off when not simple basic painless

 

Switch............

 

I have a sensor that is screwed into the intake manifold that is hooked up to a relay that controls the fan.... it is set 10 degrees higher than when the thremostat opens at 180 degrees.... works great...

 

I run a 180 deg stat and have a 190 deg switch screwed into the waterjacket that grounds the control circuit on a 40 amp relay.

 

that's what I did in our 40 Chevy, plus i added a wind up timer switch to turn on the fan after I shut the car down to help cool the motor down(if needed) on those hot summer days after I shut it off. I'd let run it for 5-10 minutes & not only did it cool the motor down but also help stop the carb from boiling over on those 90* plus days...joe

 

I did a 16" spiral blade 3250 cfm with a relay and the be-cool radiator hose sensor. By the gauge, it's working great. It's cooling a 3500 lb. 55 sedan with a cammed and beefed small block with a crossflow aluminum radiator. Of course it's a rather high draw unit, but sure doesn't run long either. So what's better? Low draw long? or fast draw quick? This set up works great on this car.

 

Revotec fan controller in the bottom hose line.
Neat little thing looks like a hose joiner,
Revotec sell 6 diffrent sizes to fit various sized hoses.
monitors the temp of the water going from the radiator back to the engine,
that way the fan only comes in if there is not enough air flow through the rad,
and stops again as soon as the temp of the water going back to the engine has dropped.

Gives by far the best result of any method tried by me,
allows the motor to run good and hot with a small rad and still never boil over.

 

A switch that goes into the manifold or block is the best way, sure you can wire it to a switch but all it takes is to forget to turn it on and it will be boiling over also if you have the room set it up as a puller instead of a pusher you will get more out of it

 

What's wrong with you guys? I'm 62, hair getting grayer every day. I use a toggle switch wired through a relay. I never forget about it 'cause I make it a point to keep my head out of my *** when I'm driving!

 

Use Switch on mine -like the idea of lighted switch and will put on my to do

 

Having to have an extra gauge, plus watch it, and manually operate a switch,
verses self contained system which does the whole lot for you,
and gives better gas milage.

Sorry got to see this one as a no-brainer if we are talking 'best' method for controlling an electric fan.

 

cause it's easier to sit there watching your gauges and hearing your fan turn on by itself .