Electric fan wiring??????

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f55079

f55079

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Hi … I’m converting to a duel electric fan set up. What is the best way to wire them up? dose anyone have a wiring diagram? mine did not come with one. Thanks everyone
 
Get a 30 amp relay and a 30 amp inline waterproof fuse holder. (assuming the fans are about 10-12 amps each)
You want a relay that can handle a bit more than the fans draw.
Make sure you have some wire, about 12ga should be good.
Get one of these.
http://www.ebay.com/itm/Adjustable-...Parts_Accessories&hash=item2c65b27985&vxp=mtr

I can draw a diagram for you when I know what relay you got, and the config of the connectors on it.

I have mine set to fully automatic, meaning whether the cars is on or not it comes on at 210 and shuts off at 190.
I pull in somewhere and shut the car off, the temp will climb and trigger the fans to come on and then shut off again after it comes down to 190.

I love it.


f55079 said:
i dont want just and on and off switch
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2 fan motors should be wired to 2 seperate relays even if both relays are triggered by a single switch.
 
1 30 amp relay with two fans that draw a total of 15-25 amps will be fine.
Now that being said, if you have a good reason for doing it with two relays then please explain.

RedFish said:
2 fan motors should be wired to 2 seperate relays even if both relays are triggered by a single switch.
Click to expand...
 
1 fuse blown or relay failed because 1 fan has a fault, both fans stop.
I cant/wont argue though. I take my clues from how these things are done in production vehicles. Factory engineers know a lot more about it than I do.
Go ask them. LOL
 
Two whole separate systems after the thermostat switch seems like a bit of overkill.
Electric fans most never die in a shorted condition, 99.9% they fail with an open field in which case the other fan would continue to run.
Lets get the guy functional, and he can mod things as he see's the need.


RedFish said:
1 fuse blown or relay failed because 1 fan has a fault, both fans stop.
I cant/wont argue though. I take my clues from how these things are done in production vehicles. Factory engineers know a lot more about it than I do.
Go ask them. LOL
Click to expand...
 
it cost more and I am not sure if it will work but it says duel fans but one is for ac. Maybe is can be changed for just two fans
 
if Spal says "a relay for each fan is required" in their tech sheet (and they do), then thats how it should be wired. i'm guessing other manufacturers say the same thing. why tempt fate?
 
TrailBeast said:
Two whole separate systems after the thermostat switch seems like a bit of overkill.
Electric fans most never die in a shorted condition, 99.9% they fail with an open field in which case the other fan would continue to run.
Lets get the guy functional, and he can mod things as he see's the need.
Click to expand...

Using 2 relay's to run 2 fan's doesn't require 2 complete separate systems. You can trigger both relay's via the same trigger and just have each relay control the fans separately. That way if one relay dies you at least have the other fan working. In this configuration it only takes 1 extra relay and a little bit more wire. The way I look at it is 15 minutes more hook up time and $5 more in parts is worth a ton of insurance for you engine that may cost thousands of dollars. JMHO
 
Using the same trigger means if you blow that fuse both fans are down anyway.
Or am I missing something?


fishy68 said:
I'm getting ready to do the same conversion and used a similar controller. May cost a few bucks but sure makes an easy and neat installation.
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TrailBeast said:
Using the same trigger means if you blow that fuse both fans are down anyway.
Or am I missing something?
Click to expand...

Correct, but that's the low load side of the equation.

This is similar to using two relays and independent feed circuits for hi/low headlights systems. If you run one power line and that fuse pops, feeding both hi and low, you have no lights. Running two circuits, if the low side pops a fuse, you still have the hi beam side as a fail safe to get stopped. Run one power feed to both fans and if that circuit fails, you have no fans. 50% of something is better than 100% of nothing.

You could always put a rocker switch to bypass the temp sensing switching system too. That way if the sensor fails, you could toggle/rocker switch it to activate the fans. A little redundancy.
 
I agree with both and Cracked and Red on this one. Sitting by the side of the road wishing you could get one fan to run might change your mind. Relays are just not that expensive, neither are fuse holder/ breakers.

Even if the stat switch fails, and even if you have no separate manual switch, you can usually easily bypass the stat switch, to limp home.

One bad fuse/ relay/ motor kills the whole deal.
 
I understand the point of two separate systems for two separate fans.
Just seems kinda overkill, since one could easily bypass straight to the battery if needed.
The thermostatic temp switch in my system is rated at 30amp because it is designed to be the relay for the fan, but I didn't like that idea very much so I just wired it up so it triggers the other relay so way less draw/heat through it.
I have a single fan system so if mine goes down for some reason not to do with the fan itself, the battery is 6" away. (Snip, connect, done)

You guys are right though, as two separate power systems would be better for a multi fan system especially for someone elses car.
 
TrailBeast said:
Using the same trigger means if you blow that fuse both fans are down anyway.
Or am I missing something?
Click to expand...

If wired that way yes, that's correct. I fuse each fan and relay separately so only 1 circuit at a time can go down if there's a problem. I also run a bypass switch to kick the fans on if the trigger dies. It may seem redundant to some but it really isn't hard at all and has never left me stranded on any vehicle I've done it on.
 
I am wiring in a Spal dual fan unit with sepatate fuses and relays. The directions are generic for use in all vehicles. Leaves somewhat to be desired. Needless to say some troubleshooting has been done to get everything working properly on a temporary basis. I still have an issue or two before I wire it in permanent with the temp switch and toggle. This website has been helpful!
 
FWIW, most late-model factory vehicles run the fans separately not for redundancy issues (Let's face it, the factory isn't that concerned about keeping you alive forever). They do that so that one fan runs normally, the other kicks on when the A/C is being used to accommodate that additional load and keep the condenser cooling. The factory shies away from running both as an economy measure, and they can do what they can to get those fuel economy numbers up.

As a measure of scale, my Neon (bone stock) has had some as-yet unknown issue keeping either fan from running for the last month, with some extended days over 100. It's yet to overheat although the gauge has started climbing if I sit in traffic. This is WITH the A/C on. Beyond that, you'd never know that the fans weren't working.

Aluminum radiators are a blessing!

I will wire separate relays and run dual fans for my Dart (aftermarket aluminum radiator) unless I get lazy and use a late-model power distribution block. I plan to try and adapt a late-model Ram condenser, drier, and lines to my Magnum pump and Dart evaporator, so if it weren't for that I would just run a single fan.

I'm curious, what temp switch are you using if you're not buying a $45 kit?
 
I would think separate relays are required for the current capacity when starting the fans. A stuck relay caused by welded contacts would not be a good thing. Also staggering the switch "on" of the fans may help reduce the peak load of the 12V bus. This may save the alternator diodes and keep a fuse from blowing. By setting the fan controls 5 degrees apart, will stagger their operation.
 
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