2G cheap fan switch install

I wanted a small and obscure switch to turn on my fans, and I found it right in front of me.

Step 1: acquire cheap flashlight from harbor freight.

You must be logged in to view this image or video.

step 2: take the rubber grommet off and pull out the switch

You must be logged in to view this image or video.

step 3: remove rear wiper plug and mark spot to drill. Be careful, it's a tight fit. Final hole size is 5/16"

You must be logged in to view this image or video.

step 4: solder some wires to the switch and epoxy it in

You must be logged in to view this image or video.

step 5: enjoy your small cheap switch with a very satisfying click

You must be logged in to view this image or video.

Note the quick disconnect connector. It'll make installing and removing the vents alot easier.


On a 2g the ecu controls the fan. Connecting pin 20 to ground will activate both fans on hi and connecting to pin 21 will activate the cooling fan on low.
pin 20 is the green/orange on the bottom plug on the ecu.

You must be logged in to view this image or video.

 

[luv2rallye]

On a 2g the ecu controls the fan. Connecting pin 20 to ground will activate both fans on hi and connecting to pin 21 will activate the cooling fan on low.

This is not true with stock 2g fans which use 2 speeds. On a 2g the stock fan speeds are not obtained by voltage on a unique specific wire pair but rather voltage on wire combinations. Read 2nd to last paragragh here for explaination: http://www.dsmtuners.com/forums/new...-issue-plus-wiring-them-up.html#post151311484.

You can control both fans (forced or ECU controlled) with just a $6 switch from Home Depot: http://www.dsmtuners.com/forums/new...-issue-plus-wiring-them-up.html#post151319397.

 

[ed1380]

Ill look into the wiring diagrams and see how it works. I'm running slim fans and just pin 20 activates both. Ill check actual fan voltage when I get a chance

 

[luv2rallye]

It's not obvious by the wiring diagrams but it takes voltage and grounds on both windings on the stock 2g fans to run REAL hi speed. I verified this by applying voltage/grounds in all combinations. Just grounding pin 20 runs both fans on medium speed. However they will run different speeds depending on engine temp, vehicle speed, and A/C. Here's the factory chart that shows all speeds: http://www.dsmtuners.com/forums/attachment.php?attachmentid=86862&d=1219990229. The relays are called (HI) and (LO) which is misleading so they used parenthesis to give you a clue of this.

Of course when you run aftermarket fans there's only on or off. There is no low, medium, and high speeds. So your aftermarket setup will turn them both on when grounding pin 20. (I now corrected my post #2 to say stock fans).