Rigging a switch to radiator FAN

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VWpowa

1,856 posts · Joined 2000

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#2 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (fastslc)

My guess is you are not running as cool as you would like. This sounds like a bandaid to your acutal problem. What kind of cooalnt temps are you running in traffic ?

 

capthowdy_1968

7,045 posts · Joined 2001

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#3 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (VWpowa)

You might want to look into running a race thermoswitch. TT sells one, I have it and I run somewhat cool. I need a new fan control module though.

 

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fastslc Discussion starter

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#4 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (capthowdy_1968)

230F if I idle for a long time or constant stop and go traffic - although some people say it's normal.. I just don't like it.
I run good mix of G12 and water.. Fairly new radiator + oil/exchanger
Oh my low speed fan is busted.. So I have only medium speed.

So how do you rig that thing ?

 

V

VWpowa

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#5 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (fastslc)

I live in Florida and i have never hit that high, well i take that back when my fans were not working i did. I would find out why your fans are not operating properly. There are a few reasons. 1 fan switch. Wiring for Fan switch. Or actual fans. I believe the Corrado has 3 speeds. I would look into doing some trouble shooting with the fans. But all you need is a 12 v source a switch and some wiring. You will have to look at the pin outs on the back of the fan. But like i said this would not be an option for me. My temps stay pretty much at the very first tick on the gauge. I would worry about any thing past 190. When my car gets close to 190 i start to worry and investigate why. But like i said when all is running like it should i stay at the first tick or a hair above

 

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fastslc Discussion starter

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#6 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (VWpowa)

I know I know

But in the mean time - how do u do it ?

 

H

hi_racing

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#7 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (fastslc)

I did it by triggering the inputs to the after-run fan controller (that little box next to the left front strut tower). Your C does (or at least should) have a three speed fan. If you do this, make sure you use diodes on the fan controller wires you modify so you won't send voltage the wrong way and screw something up.
I'd be happy to tell you wire colors but I think my C was a special from VW where some wires match the 94 schematic and some match the 93 schematic. It may take a little troubleshooting. I've got one switch for low speed and another for high speed with little LEDs just to let me know.
Remember though, just making the fans come on won't get the coolant any cooler than what the stock thermostat will allow. I highly recommend going with a 180 degree thermostat. You may even want to change to a 180 degree fan switch. Oh yeah, when you have all that apart, you may want to pressure wash the bugs and gunk out of the a/c condensor and radiator. Mine was n-a-s-t-y!
Good luck.

 

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fastslc Discussion starter

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#8 · Oct 18, 2004

Re: Rigging a switch to radiator FAN (hi_racing)

OK - this is what I came up with - remember I don't have the LOW FAN cuz it's burnt..
This is just a temp solution trying to get the fan to kick in when I want
Would that work ?

Modified by fastslc at 4:47 PM 10-18-2004


Modified by fastslc at 2:59 PM 10-19-2004

 

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hi_racing

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#9 · Oct 19, 2004

Re: Rigging a switch to radiator FAN (fastslc)

Uh, I can't tell. It's a bitmap? and I can't enlarge it enough to see. :/ Darn 36 year old eyes. Do you have a different schematic?

 

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fastslc Discussion starter

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#10 · Oct 19, 2004

Re: Rigging a switch to radiator FAN (hi_racing)

enlarged pic now http://****************.com/smile/emthup.gif

 

H

hi_racing

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#11 · Oct 20, 2004

Re: Rigging a switch to radiator FAN (fastslc)

Yes.

With a caveat: You *must* put diodes inline at terminal 1 of the radiator cooling fan thermo switch and also inline at terminal 3 of the a/c pressure switch. Make sure you install the diodes properly biased so that current will not flow back through either of those circuits.
Use 12VDC, not ground, as you can tell that 12VDC is expected by the fan control unit. If you use ground, fuse #19 will (or at least should) open.
You may even want to expand your idea and use a double pole double throw (DPDT) toggle. You would connect the other pole on the switch to terminal 2 of the radiator cooling fan thermo switch. Use an inline diode here too. This will give you the ability to select either high speed or low speed fan as conditions warrant.
As much as I can recall, this is exactly how mine is setup. I chose to connect my wires at the fan control unit so I could wrap everything up in the stock harness and make it look factory. Don't forget the diodes though!

Good luck! Let me know how it turns out.
Don

 

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EngineCodeAAA

355 posts · Joined 2003

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#12 · Oct 21, 2004

Re: Rigging a switch to radiator FAN (hi_racing)

Turn your hvac controls to defrost. It turns on the fan.

 

J

jungle

1,336 posts · Joined 2002

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#13 · Oct 21, 2004

Re: Rigging a switch to radiator FAN (EngineCodeAAA)

Quote, originally posted by EngineCodeAAA »

Turn your hvac controls to defrost. It turns on the fan.

except that also engages your a/c compressor which runs air through it and through your condenser, which creates more load on your motor, which creates heat.

let me know how you switch expirement works. I would like to put on on my gti for auto-xes and track days. Some times i have resorted to unpluging the harness at the radiator and jumpering the fans on. Only issue w/ that is that i am putting more wear and tear on those fans, and replacing them is nooo fun! Ideally one would get a pusher fan and mount it on the front side of the radiator...except there is little to no room.

 

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Pats16vGTI

5,767 posts · Joined 2004

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#14 · Oct 22, 2004

I did this to my 16v but I had it set up so the fan would be on when the key was turned to ign. You could change it up tho so that the switch turns it on there is a wiring diagram in this thread http://forums.vwvortex.com/zerothread?id=1605784

 

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fastslc Discussion starter

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#15 · Oct 24, 2004

Re: (Pats16vGTI)

I got the ghetto switch to work BUT without it, my fan (medium speed - my low speed has burnt long time ago

) won't turn on now ??
With 12V hot switching it turns on.. How often does the radiator cooling fan thermo switch go bad ? I think I don't get the 12V anymore..
I have a brand new radiator fan on order.