Electric Cooling Fans

[ivin74]

So I decided I would direct wire the fans with switches. The switches are working but its not toggling the ground on and off. I had the ground for the fan on the middle of this. View attachment 391670

You need to wire it like the diagram shown below

 

[Fless]

Wired like that will switch the B+ (12v+), won't it? How are you sending power to the fans? Constant, with the ground switched? I'm confused.

If the power to the fans is constant, and you want to switch the ground, you'll need to run the ground through the two conductors that go to the red wires on that diagram.

Using that to switch ground will probably mean that the LED won't light up, even if you put 12v to the terminal that has the black wire. Polarity matters with LEDs. I could be wrong.

 

[ivin74]

Wired like that will switch the B+ (12v+), won't it? How are you sending power to the fans? Constant, with the ground switched? I'm confused.

If the power to the fans is constant, and you want to switch the ground, you'll need to run the ground through the two conductors that go to the red wires on that diagram.

Using that to switch ground will probably mean that the LED won't light up, even if you put 12v to the terminal that has the black wire. Polarity matters with LEDs. I could be wrong.

Not sure how he is wiring it, if it was me I would wire it like the image shown below with a relay. I would run the switch thru pin 86 on one end of the switch to power and the other end ground. Pin 85 needs to be grounded to the chassis of the suv. Pin 87 is power to the fans.

 

[Fless]

He shows a 20a switch and I'm not sure that's going to survive without using a relay. Not sure how much current the fans draw.

 

[JPVortex]

I was trying to use the stock harness with relays just controlling turning the grounds on and off with a switch instead of the pcm

 

[JPVortex]

Wired like that will switch the B+ (12v+), won't it? How are you sending power to the fans? Constant, with the ground switched? I'm confused.

If the power to the fans is constant, and you want to switch the ground, you'll need to run the ground through the two conductors that go to the red wires on that diagram.

Using that to switch ground will probably mean that the LED won't light up, even if you put 12v to the terminal that has the black wire. Polarity matters with LEDs. I could be wrong.

So pretty much I'd put a ground for the switch itself and then run the ground wire from the fan?

 

[Fless]

Need to figure out which two terminals on that switch are the actual contacts for the switch. (Normally if you're going to switch power, the only reason that ground lug is there is for the LED, so it can be ignored.

You'd run a ground to the switch, then the other terminal of the switch goes to the fan relay ground. In order for that to work the relay would need to have a constant power (12v) and the switched ground.

 

[JPVortex]

Need to figure out which two terminals on that switch are the actual contacts for the switch. (Normally if you're going to switch power, the only reason that ground lug is there is for the LED, so it can be ignored.

You'd run a ground to the switch, then the other terminal of the switch goes to the fan relay ground. In order for that to work the relay would need to have a constant power (12v) and the switched ground.

ok thanks! I'll see what happens

 

[ivin74]

He shows a 20a switch and I'm not sure that's going to survive without using a relay. Not sure how much current the fans draw.

The switch is going to burn up, the fans draw about 40amps

 

[Fless]

If you know which wire is the ground that needs to go to the PCM, that would be your relay ground to run through the switch.