'05 Snow Camper, '17 170 4x4, Adventure Vissionary
I’ve installed the 7 day timer on heater booster (compared to your aux heater config) configurations a couple times. I had to send 12v to the d+ dynamo and the terminal 15 pins when the 7 day timer bacon button was pushed. I don’t think you have a terminal 15 pin since you’re is designed to work with the engine off.Have you found that the Sprinter harness energizes two DIFFERENT wires - one for the Heater Booster operation, and one for the 7-day timer?
Will the heater fire with the engine running still?
What’s odd is it worked and now it’s not working. Perhaps probe the vehicle side harness both with the engine running and the bacon button on the atc console is pushed and then with the engine off and the 7 day timer button is pushed. Are there any differences?
There is always a chance the heater itself is defective.
Is your auxiliary coolant Pump working? The one one the firewall with a coolant hose coming from the egr? Even if not it should at least try to fire up..
And it could be that load required to drive the atc wire by numbering from the yellow wire doesn’t allow enoug power to that pin.
You were right in the last half mile!!