[Howard92884]

Originally Posted by bruinbear714

I might have not been clear in my previous post... so here I go again.

Now I'm talking specifically about the fan controller. Generally speaking, with the key out of the ignition, there should be no power at all going to any devices on the engine harness.

No power to fuel injectors, knock sensor, crank angle sensor, maf, coolant temp, oxygen, etc.

This is how the manufacturer designed the wiring. As soon as you put the key on the "ON" position, it activates a relay to the ecu and powers all the engine sensors and electronics.

If anyone has power on any OEM sensor with the key out, there is a wiring problem, most likely due to ecu still being powered with the key out.

Chances are wiring is modified if the chassis has been through an engine swap.

Things are still powered when you turn your key off especially in newer cars. Whenever I work on electric fans I always disconnect the battery beforehand. Alot of cars that come factory with electric fans stay running after you turn the car off to keep the temp down.