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Electric Fan Conversion

<strike>It seems like the most logical place to put a switch is in the lower radiator hose or the passenger side of the radiator. After the coolant has run through the radiator, if it hasn't cooled down enough then the fan will come on. If it's pre radiator, I feel like it's come on too early? I'm definitely overthinking this, just curious what affect location has.</strike>
I will use the new radiators port rather than the ecu. I think having the switch on the passenger side of the radiator will be most effective because it'll show when the radiator no longer has the ability to cool the coolant down to the given temperature WITHOUT a the help of a fan. /babling.
 
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<strike>It seems like the most logical place to put a switch is in the lower radiator hose or the passenger side of the radiator. After the coolant has run through the radiator, if it hasn't cooled down enough then the fan will come on. If it's pre radiator, I feel like it's come on too early? I'm definitely overthinking this, just curious what affect location has.</strike>
I will use the new radiators port rather than the ecu. I think having the switch on the passenger side of the radiator will be most effective because it'll show when the radiator no longer has the ability to cool the coolant down to the given temperature WITHOUT a the help of a fan. /babling.

I have my switch ther and I like the switch in the lower hose better. Location in the radiator is a cleaner look.
 
Yeah idk I was being retarded that day. I ordered a 'probe' switch (with adjustable engagement) and will be using it to trigger the low speed relay on the 940 e-fan.
http://www.amazon.com/Flex-lite-31147-Adjustable-Temperature/dp/B00029J3ZW

I think I have one like that that someone sold me still unused. I did have a Hayden adjustable switch that went south will in Chicago and I was luck that I caught it. Been use a A single switch ever since. Plan to try a VW two switch just to take advantage of the two speed Volvo fan. Mine is in the radiator right now but going back to the lower hose. Seem to work better for me in that location.
 
I think I have one like that that someone sold me still unused. I did have a Hayden adjustable switch that went south will in Chicago and I was luck that I caught it. Been use a A single switch ever since. Plan to try a VW two switch just to take advantage of the two speed Volvo fan. Mine is in the radiator right now but going back to the lower hose. Seem to work better for me in that location.

I think some people use it to trigger the fan itself rather than a relay and it gets burned up. Mine will just be used to trigger the low speed relay on the 940 fan.
 
Someone posted this switch a while ago. Supposed to have the same threading as our screw-in rad switches (M14x1.5, I believe), but has a dual-range switch.

Great. But here's the thing. Low speed is on at 85, off at 80. High speed is on at 93, off at 88.
If it hits 93, does it ground both pins and run both high and low circuits simultaneously?
Is there a way around this? You could do fancy wiring so the high speed switch runs a 5-pin relay and the input 30 pin feeds say 87a and then the relay for the low-speed relay and switches the power to 87 when the high speed switch trips.
I think I just answered my own question, but it's past my bedtime.

Here's the switch: http://www.germanautoparts.com/productdisplay/19404
 
Someone posted this switch a while ago. Supposed to have the same threading as our screw-in rad switches (M14x1.5, I believe), but has a dual-range switch.

Great. But here's the thing. Low speed is on at 85, off at 80. High speed is on at 93, off at 88.
If it hits 93, does it ground both pins and run both high and low circuits simultaneously?
Is there a way around this? You could do fancy wiring so the high speed switch runs a 5-pin relay and the input 30 pin feeds say 87a and then the relay for the low-speed relay and switches the power to 87 when the high speed switch trips.
I think I just answered my own question, but it's past my bedtime.

Here's the switch: http://www.germanautoparts.com/productdisplay/19404

You could wire it up how you want. The 'switch' is just a ground that completes the circuit. On the 940 e fan you can have the big red +12 wire on the + terminal and the black one on the negative terminal..but the fan won't come on. You have to ground one of the smaller wires that trigger the relay in order for it to come on.
 
People say to use a 740 turbo shroud (still a mechanical fan shroud) but some have also used the 940 e fan shroud trimmed down. I don't think it would be a good idea to get rid of the 'flaps' in the shroud, so how is it shortened?
 
You could wire it up how you want. The 'switch' is just a ground that completes the circuit. On the 940 e fan you can have the big red +12 wire on the + terminal and the black one on the negative terminal..but the fan won't come on. You have to ground one of the smaller wires that trigger the relay in order for it to come on.


Yep. What I'm saying is what happens if both switches are grounded and both relays are on and both hi/low circuits are running. Is that going to burn out the fan?

I drew up a diagram last night of it. Should work, but the low-speed fan relay trigger feed will always be hot. So Low-speed fan will run with car off, but the relay shouldn't be drawing power while it's in its NC position.
 
People say to use a 740 turbo shroud (still a mechanical fan shroud) but some have also used the 940 e fan shroud trimmed down. I don't think it would be a good idea to get rid of the 'flaps' in the shroud, so how is it shortened?

I picked up a turbo shroud that fit my radiator then took the 940,850 fan out and mounted it in the turbo shroud. Looks factory except I had the first two nuts to the outside. Noticed it and put the last two to the inside. Still have not gone back and fixed that.
 
I picked up a turbo shroud that fit my radiator then took the 940,850 fan out and mounted it in the turbo shroud. Looks factory except I had the first two nuts to the outside. Noticed it and put the last two to the inside. Still have not gone back and fixed that.

Where did you get your shroud? What vehicle? And I assume you did this conversion on a 240.
 
Think you are right! What ever it is , it a perfect fit.

I hacked the 940 shroud and left 1 inch open on one side so air could get through. At first I left no airways and it got warm on the highway. Cutting that 1 inch off brought it back to normal temperatures. It also stays cool with the fan on even with that gaping 1" hole:lol:
 
I had a 940 fan and modified it and now that I think on it a little if was a 740 turbo that had the shoe shroud. I have a couple of the 240 off set turbo shrouds that will work but more bulk. Plan to take a look and see i Like it with a electric fan. I could mount a electric fan in the same way.
 
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