1994 mustang cooling fan wiring?

[brad rozum]

1994 mustang am wiring a aftermarket 2 wire fan to be controlled by my ecm. Is it possible to wire the low and the high speed wire to the positive wire on the fan and have the fan run on low and high speed controlled by the ecm or will I have back feed problems? If need be I can I just wire it to the high speed power wire and tune the computer for the temp I want it to turn on?

 

[ttocs]

Why are you swapping out the stock fan? I think you could wire up a relay up to allow it to go to high speed when its on and then low speed when its not by wiring up the low speed to 87a, and then connect the high speed to 85 and 87, and then 30 out to the fan and 86 to ground.

 

[brad rozum]

Because 15 years ago when the car was my primary drag race car the stock fan wouldn't work with my radiator and wouldn't pull enough air. I'm wanting the ecm to control the fan and take my manual fan switch off

 

[ttocs]

The way I described the relay above I am pretty sure will work. The only part I would mention is that you might need a high current relay to handle the amps pulled when it first fires up.

 

[brad rozum]

So from the car wiring the low and high speed wire goes to separate terminals on the relay, then from the relay the positive and negative wire to the fan

 

[ttocs]

The relay will only switch the + portion of the high/low voltage. The ground wire from the fan can go to pin 86 and then ground both the relay and the fan to the chassis

 

[brad rozum]

Sorry I'm not good at that stuff. Would u have a diagram?

 

[brad rozum]

Would I wire it like this and it would function on high and low ?

 

[ttocs]

Sorry I'm not good at that stuff. Would u have a diagram?

not for this and I am not skilled enough to make one. If you look at the bottom of the relay the numbers are next to each pin. Take on wire at a time, crimp an insulated spade connector on it and then slide it on the correct pin.

Would I wire it like this and it would function on high and low ?

Not sure what this will do either to the ecu with the two fan wires connected but it might keep the fan on.