Tech Tip Tuesday: How to Power Electric Cooling Fans... Must See!

We pride ourselves in creating and building quality and usable cooling systems for street and race applications. There are so many components, one of them is the fans being used. More importantly powering and when to turn them on and off. This video covers the lifespan or lack thereof in relation to turning them on and off. This is tried and true info derived from real world experience on Drag Week, Rocky Mountain Race Week and more!

[@SilentNight1647]

I literally make my living designing industrial control systems and if it is one thing I have learned, the guy who designs a fancy control system rarely has to live with it. The guy who maintains what he builds designs a simple, easy to understand, and robust system that doesn't have fancy features but works whenever you need it to. These are great tips gentlemen, keep it up.

[@MotionRaceworksOfficial]

Dustyn Jensen so true! The KISS system wins everytime

[@cuzz63]

As a technician in a factory I can attest that you speak the truth. We have too many engineers that design overcomplicated machines that are hard to diagnose then repair.

[@jamesbergeron8356]

I too make my living with industrial controls, this is good advice. Simple and robust is always the way to go.

[@johnp487]

I don't agree, a properly built control system with brushless fans will make for a very efficient, reliable system. Reducing amp load with soft-start prolongs the life of your battery/alternator and overall increasing reliability of the system. I work for DeltaPAG. We manufacture brushless cooling systems with quality digital controls. They're the LED light bulb of fans. An LED lightbulb is far more complex than a candle.

[@alchampion340]

I may have to try this young fellas brushless motor because I want to integrate my fans with and electric water pump that will cool even after I shut the engine down. Oh by the way, I’m not a fan of the LED lights at all. But I will look into your brushless motors.

[@rd95stang]

I'm glad you touched based with using a relay for the fan, I work at a parts store in South Texas and I see so many people say screw it and just run a switch and wire to the cooling fan just case they get intimidated by the fact that there are more than 2 wires

[@Ampman007]

Toss a 1000 uF electrolytic capacitor across your leads of each fan. Will help each fan to “kick over” as it phases current and voltage about 90 degrees at best. Enough to get that electric fan motor to kick over with no strain on the electric motor.

[@donttreadonme9132]

Very relevant video for me. I'm in Colorado dealing with cooling issues. I have my fan on a switch (with relay) and turn it on/off way to much evidently. I'll follow your instructions from now on.

[@stanleymorton2992]

What I don't like is my fans running when I'm on the highway. Seems to be a waste, Other than that exception, I tend to agree with your hypothesis.

[@mitchm3394]

We sell higher wattage electric fans than those in this video at www.americanvolt.com/collections/electric-fans which includes radiator mounting kits. Various thermostat switch turn-on temps and NPT thread-in sizes available as well.

[@MJTAUTOMOTIVE]

If you are going to wire your fans up using a switch. Put an idiot light on the dashboard. So that it is illuminated when the fans are off and goes out when the are turned on. I have seen and repaired alot of engines from being over heated due to the fans being forgotten to be switched on. You should also use a Mechanical Temp guage that way if you have a electrical issue your guage will still work. Another tip is if you have round style guages (almost all of them are) orientate them so at normal operating temp the needle is pointing straight up. That way at a quick glance you know if you're temps are fine. I also set the oil pressure gauge like this as well. Might sound a bit weird but in a road race car it really helps. One quick glance and you know if you're good. One more thing use a Mechanical oil pressure gauge as well. But use braided hose for the feed line not the poly crap that comes with some guages. The last thing you want is the feed line to burst spraying hot oil all over the engine or all over the inside of your race car.

[@teamdrama6251]

Diffenitly agree mechanical gauges for oil and water .it cost me 10 grand losing a race over a bad sensor the race pac said 270 .so after that every car mechanical gauges plus race pac gauges. That was a hard lesson to learn 10 grand over a 30 dollar sensor. Damn .lol

[@Sloppyjalopy123]

Just wanted to say I enjoyed the hell out of watch your RMRW. Something enjoyable about a low-buck pig!

[@Platinumtag]

Greats tips I always advice other to run the fans full time for those overheating issues with a aftermarket relay and never fails.

[@johnburch6927]

Good advice, meant to maintain temperature, rather than cooling it down when it's too late.

[@supercoupe28]

Awesome info Doug. Laying it down, so everyone can pick it up. 👍

[@captnjoe40]

I use tinned marine grade wire and connectors on all my vehicles. Those parts make automotive specs look like junk. I never have failures from corrosion, connectivity, or amperage overload when following ABYC tables. There is a little price premium, but my wiring is always one and done. Also, don't forget a lot of strain relief and chafe protection.

[@MotionRaceworksOfficial]

That might help right up until the electrical components. Can’t control what’s inside the motors relays etc

[@Sleeperdude]

Good tip I totally agree

[@baysidefabrication]

Great video!!! I’m actually planning rear cooling system as we speak.

[@jcnpresser]

Great tip as always, only thing I’d add is putting trap doors in the dead space in the shroud, helps with air flow when driving down the highway.

[@Fishtricker]

Maybe you can help me. 2002 s10 zr2 4.3l electric fan conversion. I see 97 degrees in summer regularly, I run 32” tires, A/C, and haul a 2800lbs bass boat. The drag the clutch fan produces is worth the conversion but…I cant get the engine to stay below 220 degrees at 55mph or faster. I have 2-12” flex-a-lite fans with an aluminum shroud. eBay 3row aluminum rad, and a ebay relay harness, 195 thermostat. The A/c is cold and engine stays cool at an idle, much better then the clutch fan (missing half shroud) but when it starts to work on the hwy is wants to get hot. It’s a v6 I don’t understand why I’m having so much trouble. Any suggestions would be greatly appreciated.

[@jbuch66koop]

I beg to differ, on your comment that 160 is too cold.. Its not dangerous but my motor made 13 more hp from 160-190.. The engine is definitely more efficient with more heat and with temperature, comes pressure, that's why the OEM systems are higher pressure because they run at higher temps. A motor running at 220 is not dangerous, most race cars in professional racing, run their motors between 220⁰-240⁰, like Nascar or IMSA style cars. I see your point with the mountain theory though, but going from 190 to 210 is fine.

[@Floordford]

If you have a temp probe switch and a manual switch, make sure it isn't a light up toggle switch. When that toggle is off it grounds the signal wire to the relay.

[@gixxer750axld]

I ran into this TTT yesterday , my car ( LS gen 3 iron 6.0 N/A) always ran on the really warm side, almost like the factory truck 210*. So on my way to shop I went into my Holley system and changed both fans to come on at180*( off at 160*) and BAM even in slow traffic the car was running a lot cooler , I live in central FL. where it is hot and humid. Good tip! See ya at Bradenton No Prep!

[@jeffreyeiford2750]

Hi Doug , what Radiator would you suggest for my 03 F150 4.6 truck ?? Daily Driver Thanks Mouse

[@mikeydejon2148]

So I bought a camaro with eltric fans I've never messed with them before. Car has a 327. It runs like 200 n 210 when cruising hot. If I sit at stop it'll go to like 215 220 depending on how long I sit. Which then I kick fans on but it takes like 3 to 4 minutes sitting still to really cool down. Basically what I've been told it that I only should use them when stopped that if I put them on while driving its doing opposite of cooling. Might b confusing to u but I'm kinda stumped lol I just wanna turn it on n not worry about it😂

[@xb70valkyriech]

Really simple way to have them turn on at startup without worrying about it: have the ignition energize the relay, and use a self latching relay (relay that locks itself to the on position once power starts to flow to the load). That way the fans start when you crank the motor, and stay on until you kill the power. I can explain more if needed, I know it's hard to communicate this idea through a KZbin comment.

[@colesteven1123]

Isnt drag week right around the corner? Simple Google search will answer, but im busy watching the video on mobile

[@colesteven1123]

September Was wondering how much time the guys who participate in both have between events. Now im curious if DW was postponed due to wuhan wheezer

[@shaneonews6791]

Running fans on at a speed of 30-50 60+mph is pointless... The air coming in is greater then the fan speed . Fans are only used when at lower speeds or idle. So this guy is wrong. The only way to keep your fans on on higher speeds is if you have open shroud. Which let's air pass threw around the fans.. This guy doesn't know what he's talking about.

[@lesbenson54]

Thanks for the advice. I have a new cold case radiator with dual fans on order. Will call Jegs tomorrow and cancel the thermostat controllers and go save 75.00.

[@adriane7841]

In 4 Nova update. Curious what happened to the racecar

[@MotionRaceworksOfficial]

Adrian E coming later this week or next

[@mikeydejon2148]

I have mine setup exactly how your holding that in the engine bay. Should my fans be blowing air towards engine or towards like front of car

[@steveshortt90]

Yes definitely cannot hurt the motor running fans from start up / cold because the vehicle utilizes a thermostat. Coolant inside of the motor reaches temp before allowing cooler coolant from the radiator to enter the motor. The only thing you'll do to the vehicle is create more load on the alternator, increasing fuel consumption. Twin 16" Extreme Spal 3000cfm fans pull 50A to 60A.

[@docfischer7291]

Probably one of the best fans we have used were out of a Lincoln Mark Vii. I think they are like 5000 cfm. New Ford trucks even have 3000+ cfm. With a double pass or triple pass radiator you should be Golden . All my cars ran electrical fans running from start to stop. It’s a thermostat that will help you regulate.

[@738drvr]

The Mark VIII fan moves 3900cfm of air. One of the best OEM fans but still a brushed fan. Starts at 60A and then falls off to 30A within a few seconds. Use brushless fans. Last longer and don’t use a lot of amps and you don’t have the big spike at fan start.

[@calhayward7921]

Sorry Doug, but if you are running E85 and those cold coolant temps 👎🏻

[@2jzlex]

Thanks Doug! Finishing up my build and this is useful, I was planning on wiring both fans separately at different temps but I’ll just keep it simple

[@Blaydrnnnr]

I am about to do a dual, 2600cfm total, 25A each, electric set up in my modified 2wd short bed Ram, and was REALLY hoping you would touch on where exactly, you tap into for your switched power source for the relays. I have a hard time figuring out a good, clean switched source when I need to install a mod. Good vid though.. everything made sense. I just want mine to come on at around 160°, and stay on till after I shut down.

[@chrisdogmlb]

What about a pwm fan controller that speeds up based on coolant temp? Would the same apply or is that just for full on or off that you are talking about?

[@DUKE-bc4ig]

So I can just have my fans turn on when the truck is on and have them shut off when its off and it wont hurt anything??

[@thisismossop]

I was expecting this to be the standard 'Relay' video, but turns out to be far more useful. Quick question, does all that apply equally to smaller, modern engines? 4 & 6 cyl, 2000cc engines etc.

[@austinbrown924]

Haha same considering I've never used relays I almost didn't watch it

[@ratherbeboating10]

My new setup is pretty basic. I took and modified the stock setup. So I added two pushers on the A/C condenser that run all the time when the fan I commanded on. This helps with low speed as they pull air through the cowl. Those are aftermarket. My main puller is an OEM unit made by siemens and runs on 2 speeds. The low speed maintains temps with A/C off and the high speed is on when the compressor is commanded on. I have it programmed on at 195 off at 185. (I run a 180 stat because I enjoy heat in the winter and the car will run against the stat even in the upper 90s) so it is basically this... car hits on temp, pushers and low speed main comes on. Car hits off temp, all fans shut off. A/C switched on, fans come on high and pushers come on. Now the ecm shuts them down above 35 mph... I did a bunch of testing and they don't seem to help above 40 and honestly on the highway it seemed like the car ran hotter on vs off. So I just leave them off above that speed. Runs fine. I try my best to use OEM parts for things like that, they make for the most part, the most robust aftermarket parts look cheap. Now on the 67, the spal unit pretty much runs all the time. That 14 inch unit is a beast but it doesn't flow as much as the oem on my car. But the rad is substantially larger so it doesn't need the flow.

[@terrywilson581]

Great ideas tells a bunch of dummies what they shouldn't be doing love it 👍👍👍👍👍😃

[@travspumplife]

This episode definitely falls in the category of: Wait why do that its the right way to be done!!🤷‍♂️

[@arvinjessee-zx4mc]

I turn my fan on the alternator quits charging.

[@jean-guylebreton5332]

I’m glad I caught your video,that really make me learn a lot

[@bradpittman5075]

Yeah wiring for sure. Note, generally mil spec wire 12g is rated at 24 amp, mil spec 10g is rated at 33amp give or take an amp, just a thought when choosing wire size. If you have a bunch of garbage connections it will make more amps, and relay each fan. Switch the fan via the ground on the low side of the relay like ecus generally do, if you choose a toggle. I agree with the statements on letting them run for sure. If you are badass and have a power distribution module you can monitor the amp draw on your fan circuit. Maybe do a test with wire size and different crimps and watch the current draw in different scenarios. May be helpful in visualizing. Also, the cars rattle and shake and vibrate all the time non stop. I always try and strain relieve terminations. It’s a little more difficult on the larger wire for pumps and motors but helpful in longevity. Generally we are not pros just hobbyists so every little bit helps. And to my way of thinking and I will say I am very value oriented, spending the money on good wire is a must especially after a 4-600 dollar pump, 2-400 radiator and whatever fan you use plus plumbing. Anyways good luck. 🇺🇸 first.

[@RobertSiwik1968]

Thats the best advice ever! I do exactly what you said and have been for years ! You know your stuff man!

[@whackbag3606]

The load on startup is so true & what i don't think a lot of people understand. In higher voltage applications, especially industrial, motors use & need a capacitor to "jump" start and get them going.

[@bps.1]

like the video alot and i think that every one who has eletric fan in their hot rods or what ever should take your advise

[@joesautorepair9518]

How do you keep fans on after they turn on at a certain temp in Holley terminator x software? Love the tech tip tuesdays!

[@PeterHatch-mx7zc]

Where do i buy a radiator like this one in video please

[@Bumblebee4788]

Methanol, who needs a stickin cooling system? :)

[@buddyrebel_Garcia]

Where can I buy this for my 2006 Pontiac GTO? I have a LSA swap GTO and my stock fans aren’t cutting it. Today it was 99 defrees and it overheated. Engine temps were 235 and top 240. Had to pull over. I have aluminum rad so I know it’s the stick fan not keeping up with the high horsepower.

[@ray6976]

I have 2 fans on one relay..thats how it came. Added a 150 amp alternator thats getting 14v running. Fans kick on and vibrate ans surge the car..if i unplug 1 of the fans it works fine. Do you think having 2 fans on one relay would cause this?

[@christopherdowning7776]

As an auto mechanic, I know that condenser fans turn on and off and cycle all the time. Maybe you are using cheap fans. Also you need the coolant to stay at 190-200 for optimum engine performance, emissions.

[@paulthompson8480]

hi , 1/ A decent controller with 1/ staggered start 2/soft start 3/PWM controller for brushed fans is available . 2/ brushless /Pwm fans ,, beaware many aftermarket fans can draw alot of power . Shop around

[@Tater79bj]

Probably been asked a million times, but are you and the guy on lunkers KZbin channel related?

[@BAHRacingTeam]

I’m building a 700hp ls powered 1989 mustang. Drag strip only. What radiator and fans do you recommend? I’m also going electric water pump and curious what gpm do you recommend? Thanks

[@hueyrotorhead]

I’m changing over my Foxbody clutch fan assembly to electric. I will be using a factory SN95 electric fan. So using the proper size wiring and relay, just run it on all the time? I did this with my Ram a/c fan after controller failed. No issues for years doing that.

[@yolofullsend]

Doesnt matter if the fans are running on warm up, the thermostat isnt letting the engine coolant circulate through the radiator.

[@ewitodaaabeaner9643]

I’m ls swapping to a 6.0 gen 3 on a Chevy single cab can these fans work for mine like I’m new to this stuff and been wanting electric fans

[@longshotdiedtired1582]

Please tell me where you got the radiator hose from or a video link that’s sweet

[@markgiraldes4062]

He sells Fragola hose FYI and will help design systems 👍😎

[@QXZ9027MKII]

Much Obliged Sir for the insight, my 2 cents invest in a PWM Controller. Much Robust, less noise & more easier on the charging system.

[@WILL-jx7wg]

I’ve got it wired to my Ignition switch so when I turn my car on it turns on. The car is a tbss so it has no problem reaching temp fast. each fan has a relay and a 30amp in line fuse all wired with 12g wire

[@milkhouse01ja]

I leave my fans on and I still run 210 in a car that only has 400hp. Do I need bigger fans

[@WARESPOWER]

Good information thanks

[@justinhobart8747]

COOL.... Tech tip Tuesday 😁👍

[@ktga67ish]

I wonder why he didn’t touch on the thermostat in the system. The t-stat would shut off/open up water flow to the rad regardless of what the fans are doing. So the fans could be cooling the rad to 100 but if the t-stat is a 185 then that’s the lowest the engine will go after it’s warmed up.

[@M9Only]

I don't think they use thermostats in their racing applications, and I think (according to my limited knowledge of cooling systems) you don't really need them unless you live in freezing weather. as Doug said in the video, running the engine a few degrees lower than its operating temperature increases fuel consumption a little bit, that's it. I'd rather spend a bit more on gas and run it cool than blow my engine in case of overheating

[@ktga67ish]

Mahmoud Mostafa You can always get a 160F thermostat. IMO if you’re going to be putting a lot of miles on your engine before rebuild than it would be a good idea to install a thermostat to reduce the warm up time and increase longevity. I guess with the street strip cars they aren’t as worried about that since they typically get freshened up bottom ends every couple seasons or less.

[@TqSNv9R0iG5Ckxew]

I'm surprised by how small those radiator hose openings are. I think my heater core has bigger openings.

[@longshotdiedtired1582]

Great tips I can definitely see where fans switching on and off would drastically decrease life span of them

[@2cargarage163]

This is super helpful for me! I have a camaro that’s 1000hp and the fans stay on at 196 and never turn off…which always worried me but now I’m not as concerned

[@bseries8826]

I'm a big FAN of you guys 😉

[@markandfrancis]

Hello, what are your recommendations for an application when running AC? Just have the fans run continuous? Wire a fan to run when AC is running?

[@doylewiggins1615]

I’m switching through the relay, what switch make do you recomend ?

[@benb2953]

Pulled one out of a crown Vic and dropped it in my f150, wired it through a relay to my switch in the dash and it has run flawlessly for 10+ years

[@Raysandfamily]

I have a lunati 280/290 cam in my 305 Sonoma that I'm building I want to put pusher fans this will be my daily using my 4.3 rad what fan do I use

[@stonerman15]

I have one fan on one backside and another on the front. I didn’t do it this way. How should i fix it? A two fan shroud kit or what? What would you do???

[@charliemclaughlin1042]

All I have in my Silverado is a single fan from a 90s Chrysler car I live in las Vegas it gets 115 degrees here all the time I have no problems my fan comes on when you start the truck and off when you turn it off I have always ran my cars like that and never had any problems 👍👍👍👍👍👍

[@MyUndefeated]

So from my understanding I should just run a toggle switch to a relay to the fans? And leave them on from when engine gets to temp then when I shut the car down?

[@Jwoudstra2683]

My question would be if you’re running a dual speed fan does it hurt to have the high speed triggered by a temp but always have the low speed on when the engine is running.

[@joedoakes8307]

YOU , forgot to TELL US who makes the highest quality FANS !

[@bobbysenterprises3220]

If they are cycling they are big enough they should be on a two speed or variable speed. Even a simple resistor. The brushless would also be better. Not only because the current draw is lower because you can do softer start from the controller but can also do variable speed.

[@Nicholas-im8bd]

My 2000 ws6 has a dual pass griffin with two 2200 cfm badass derale pushers using the 3 relay two speed control with Holley controlling the on off temps. Low speed on at 185.... they pretty well hold the car at 195... at long stops the high speed turns on at 200 for a second then right back off. Not bad with the t6 right up against it on the other side

[@robbigemon1868]

What switch do you recommend for running fans i got a cheap 30 amp led switch. But i did run switch to a relay then to duel fans I guess i need better fan car still runs hot to me about 190 to 200

[@ricklamb772]

i have a question,do the fans cool better pushing air through the radiator,or reverse the piloraty anddraw air in through the radiator?

[@aureliogarcia1223]

Checking out this video Just in the Nick of time when I'm in the middle of setting up my two fans on my 68 El Camino. Relays, fuse holder and much more, thanks!

[@nathangresell1534]

Would a duo of standard radiator fans be able to run in series? I know they will spin slower than parallel and i know the difference but will the fan motor survive at 6-7 volts? Has anyone tried it?

[@5HKNB4K]

Hey come to find out I've been doin this right 🍺🍺🇺🇲😁😎

[@k20Fritz]

Oddly enough I want to know how a rmrw car could benefit from a quick connect second rad? Could it help for street driving a 1000 plus hp car?

[@malcolmyoung7866]

Great info and thanks for the reminder regards not switching straight to a fan but via a relay...

[@xskinyx]

Why does it matter if you "over-cool" the water? Doesn't the thermostat regulate the water temp?

[@gmangasco6700]

Can't you just hook your fans up to a temperature sensor with the relay to have them kick on and off it's a serious question can someone give me a serious answer

[@hondafreak8613]

Why do manufacturers use huge radiator hoses like 1.5 to 2.5 inch. But racers think -16 fittings are good enough. Thats a 1” hose running a 800hp beast. Can’t cool a engine if can’t circulate hot coolant from engine.

[@MotionRaceworksOfficial]

Not think, we know the -16 works… cools racecars and Raceweek driver cars that are the most demanding on cooling systems. All you have to know is that it works

[@johnwilder7301]

What amp alternator too use when running electric fans

[@BOOT]

OEM fans for street, if yo can fab something up

[@davidcunningham00]

15 years ago I did a efan swap on my brono2, I found out the hard way that a toggle cant handle the power for the fan, now days on my nova and my chevy pickup I have efans and with 8 gauge wire to everything.

[@anotherbluenova6358]

I was just sitting here trying to figure out a cooling strategy to uncomplicate my fan set up when I found this video. You just saved me some money. Off to Summit I go. They are my local speed shop.

[@m.scottmunger4685]

Thanks. First big build and was wondering about this.

[@rkspeedSicario]

Do y’all sell custom radiators with fans?

[@thomasdemarco617]

what direction should a puller fan rotate

[@jonprice1623]

Awesome video! Do you still run a low temp thermostat on a 500-800 horsepower dual purpose car or the moroso style washers or no thermostat at all?

[@onememories8523]

Great video ! Thanks for sharing !!!

[@nymustang5084]

Id be curious on the Thermostat debate for a future Tech Tip.

[@731u.s.a5]

Guess us Orr’s just all build cool shit haha

[@frediefarmer]

👍🏽🇺🇸👍🏽 awesome video