electrical question

[svwc]

I would like to have the high speed fan on the heater to turn on ONLY when the engine is running. I'm thinking of running the power through a relay switch, using a switched power source to switch on-off.

I looked around under the dash, and cannot find a switched 12v source.

does anyone know where I can find a switched 12v source, or can I go to the alternator?

2011 SN 200 Limited with Linc system

[gmdattilo]

the red wire is hot when the PME is activated. you could pick this wire up near the radio if you cant find it elsewhere. the purple wire is hot when the PME is commanding the engine to run. you can pick this wire up at the dead man switch. its the one coming from the PME, not the one going to the motor. any black wire from the PME is negative.

the big stud on the alternator is connected directly to the battery thru the circuit breaker. its hot at all times.

[svwc]

thanks gm
I'll let you know how I make out

[svwc]

as promised gm..

Thanks, it works!! this is the way it should be from the factory

the high speed heater fan run only when the engine is on, no more cold air!!

found the proper purple wire at the lanyard, that was 12v only when the engine was running, and using a relay switch, spliced into the orange high speed fan

[gmdattilo]

glad it worked for you and thanks for the update