[MadMacks]

I’m hooking up a new radiator that has 3 electric fans, rather than a clutch fan and a single electric fan. I’ve connected one fan to the original fan circuit, controlled by the PCM. I’ve connected the second fan to a new relay driven by a new coolant sensor. And I want the third fan to be on whenever the engine is running. But, right now I’ve had to connect the third fan using a trigger based on “key on/accessory on” as I can’t identify any existing circuit that energizes only when the engine is actually running. Of course I’m using a relay.

I can wire in a switch to my current (pun intended) set up that would allow me to run the radio, for example, while the engine is off and not trigger the fan to run, but it would be simpler if there was an existing circuit I could tap that only energizes when the engine is actually running. I could trigger the relay using that circuit.

Anyone know of a circuit that only “powers up” when the engine is actually running?

 

[warriorsuspensions]

The only one I can think of is the fuel pump. Comes on for two seconds and then again when engine starts

 

[MadMacks]

I guess I can use a 10 second delay 5-pin relay instead of a standard relay. Or just wire it into my VOSwitch UV100 controller and manually turn it on and off.

 

[Gluckmysock]

I did an alt relocation and Taurus fan install here is my write-up Taurus fan install I use 2 toggles in the cab. 1 controls the factory electric fan and the other Taurus 2 speed fan. there are links and wiring included I did and an led light in the cab so i know if the fan is on. I cut the wire from the ECM that turns on the factory fan and put in through the toggle. I can turn both fans off if I go under water. and I do go under water. Keeps from shorting out the electric motors. It's at least worth a read.