vtraudt

I removed the 'pusher' fan in front of the condenser (make room for FMIC) and replaced the visco clutch fan with electric fan.

Can I just wire the electric fan to the (now unused) wires of the pusher fan?
When is the pusher fan turning on? Jus when AC is used? Or at a certain (which) coolant temp?

The E fan came with a thermostat, but it is a fixed temp, 3/4 inch plug. I don't see an option to use the thermostat to control the E fan, or?

From Audi guide about the coolant control (links below), I am not sure what turns the pusher fan on (and if the controller could drive the E fan motor):

Metronet

I use a PWM controller on my allroad to power the electric fan (that replaced the viscous clutch fan) and it works very well:

WWW.AUTOCOOLGUY.COM

vtraudt

And where do you get the trigger signal from to kick on/off the fan?
Not so much concerned about controlling the fan speed of the E fan. On/off (based on coolant temp AND A/C) would be enough for me.

Metronet

They have a few options for the temperature adjustable PWM fan controller:

AutoCool sensors

I opted for the "copper" sensor where I slid underneath the rubber hose attached to the thermostat housing. (I have an aluminium housing, probably won't work with a plastic one)



For just On/Off using a relay or using existing wiring for trigger this might help:

https://jhmotorsports.com/instructio...gram-Notes.zip

odoboyusa

I am just doing the same thing on mine and i plan to wire the new electric fan to the plug where the front fan was connected.
The front fan would run when the engine got too hot and also would run when the ac is on.
In my case, because i have the thermoswitch mod, it would also run after the car is shut off hot.

So adding another fan controller would be redundant on cars that have the front fan (most 2.7t).
The existing fan controller also used pwm control for soft start and all that good stuff.
If you really want to control when the electric fan kicks on, you could override the lower radiator hose temp switch (the blue one) - that has two internal switches, one turns on at a lower temp and the second turns on at a higher temp.

vtraudt

So just plug the E fan into the wires from the pusher?
Is the pusher really coming on at fairly low coolant temps? I thought it only come on with AC and REALLY high coolant temps (passenger side fan come on earlier)?

Is the coolant temp switch (in radiator) a '2 settings' switch (one to turn on first fan, 2nd temp for pusher fan)?

With the visco fan gone, I want the E fan to kick in at same temp as passenger side fan, and with A/C on.

odoboyusa

yes, just make sure when the fan is on is pushing air from front to back of the car.

If you look at the diagram you posted, it says both fans run at the same time.
yes, the coolant temp switch has two separate switches built in.

and your last phrase is exactly what's actually going to happen.
very few cars have visco fans and are just fine. my c6 a6 has two electric fans from factory and runs just fine.

cooling fans for the radiator/condenser are only needed at low speeds.

vtraudt

Will wire it up to the pusher fan. See how it works.

vtraudt

IIRC, when I did a temp wiring to the pusher, it did NOT come on when the passenger side fan kicked in.

odoboyusa

I will soon try this myself but per the images you have displayed it shows both fans running at the same time, it never says anything about fans activating independently.
I will keep you posted.