Fan Cut Off Switch?

Fuze911

Fuze911

Forum Member
Joined
Jun 11, 2010
Messages
214
Location
Owings Mills, MD, USA
Car Year
2007
Car Model
Impreza Wagon 2.5L
Transmission
4EAT
Hey guys, Is there a DIY or post somewhere on how to do a fan cut off switch? I hear that if the fan blades touch water during crossings it can cause them to hit the radiator and crack it? Is this true? Should i be worried?

I want to take the car on a camping trip and orv trail and the trail has alot of water crossings that got me worried. Any advice?
 
One way is cut the Positive at each fan and extend the wires back to a place in the car where you want your switches reconnect the wires with the switches you need to keep the fans separate because one fan all ways comes one with the AC you can use 1 double pole switch or 2 single pole switches

I plan to do this very thing just haven't had time.

Nate
 
I earthed both of my fans into the cabin and just fitted up a switch on the dash board to disconnect the earth. Not sure what the difference between a power cut off and earth cut off are but both work.
 
Venom said:
I earthed both of my fans into the cabin and just fitted up a switch on the dash board to disconnect the earth. Not sure what the difference between a power cut off and earth cut off are but both work.
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ACtually the earth cutoff reduces wear and load on the contacts. Thats why almost all switches in cars and relays are on the earth side of anything where possible.
 
Fuze911 said:
I hear that if the fan blades touch water during crossings it can cause them to hit the radiator and crack it? Is this true?
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Yes it's true unfortunately. :o

If you don't have the fan cut off switch & do happen to come across a water crossing, you can always put a tarp on the front. :iconwink: :)

Regards
Mr Turbo
 
mr turbo said:
Yes it's true unfortunately. :o

If you don't have the fan cut off switch & do happen to come across a water crossing, you can always put a tarp on the front. :iconwink: :)

Regards
Mr Turbo
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Cool, thanks guys. I gotta give this a go this weekend! So ill have to run a couple wires to ground/earth in the cabin and run a switch off that. Ok. Sounds simple enough.
 
Build a light or, preferably, a BUZZER into the circuit, which comes 'on' when the fans are 'off', so that you DON'T FORGET to turn the fans 'on' again! :poke:
 
Great idea! thank you. Ill be doing the diff breather, diff skid plate and this fan cutoff switch sometime this weekend.
 
Please post pics of your work progress and finish. it will help others.



Nate
 
Fuze911 said:
Ill be doing the diff breather, diff skid plate and this fan cutoff switch sometime this weekend.
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Yes please show us pics of your work, as well as reading & seeing DIY's, it's also a great source if info for others.

Doing diff breathers is a piece of cake. Breathers Post #11 will explain it all.

Regards
Mr Turbo
 
Thanks again guys. Yea i will be sure to take pics. I have a week to get this all done before my trip. :\
 
Last night i had a couple hours so i tackled the Diff breather mod. Very easy to do thanks to the DIY you guys posted. THANKS! Dropping the diff was a brease.

I looked at the way the fans are wired and it looks like it will be easy as well. Will have to cut the ground wires, cap the ends and run a wire from both fans to a ground in the interior and run a switch off that. Basically like described before.

Its raining hard here today so it looks like unless i do this super early friday morning i will not have time to get it completed.

How worried should i be? These water crossing are about a foot in depth max. There is about 10 of them scattered through the trail. Should i take it slow? Should i go quick? Should i pass them on the side in the shallower ends?
 
As slowly and as shallow as possible.
At that depth it wouldn't be surprising if you create a 'bow wave' that would allow sufficient water in the air intake to hydrolock the engine.
This is entirely separate from the 'fan as propellor' issue.
 
I'd be checking out where your air is collected from! I know the L's air intake is behind the RHS front indicator that's mounted in the bumper bar - so it's pretty low! I've seen a few L's fill these up with water followed shortly after by the engine :(

A cover over the general area might help, this is what I did on my last "deep water" river crossing.

I've also made a circuit for my L where I can trigger the fans if I want them on over the slow stuff. An On/Off/On switch allows me to also have it set back to what the factory setup wants the fans to do. I used a diagram for the L's wiring, being earth switched it can be interesting at times ;) I'd upload it but imageshack isn't letting me do it. I'll have to do it another day which really doesn't help you out at the moment.

All the best with your trip!

Cheers

Bennie
 
Thanks guys!

The trip was a HUGE success! Lots of fun. I will post pictures and videos from the event as soon as i can get the edited. Also ill post my DIY "inbay" snorkel so keep your eyes peeled! lol
 
wiringdiagramthermofanw.jpg


Got it from my build thread about Ruby Scoo. Pack a lunch for that one if you have a look ;)

Cheers

Bennie
 
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