Is there a way to find cooling fan signal at ECM?

[John Larkin]

I was thinking of putting a small light on my pillar pod to let me know when the cooling fan turns on. I know I could run a wire from the front of the car but if there was a wire at the ECM that would be more convenient. EDIT - I figured it out. D1 wire off the ECM. I'll hook up something temp tomorrow and see how it works.

 

[dsapper]

It looks like D2, dark green, might work but dont take my word for it. here is the pin-out diagram

http://www.vortexbuicks-etc.com/ecmwiring.htm

 

[TurboDave]

If you'll notice on that wiring diagram, that is the low speed fan relay control signal. It's an active LOW. IOW, you have to have a keyed source of 12v to one side of the bulb, and the D2 signal would provide the ground when the ECM activates the fan.

 

[John Larkin]

Right on. I will look through the open spots in the cluster to see if there is an idiot light slot that would make sense to illuminate.

 

[TurboBuRick]

Right on Dave.

John you can test the green wire at the low speed relay as well.

Rick