Inspired by a thread I saw on g8board.com I built my very own remote heated seat module. It’s actually a pretty simple circuit. It simulates the pressing of the heated seat buttons automatically when I remote start my car (G8 GT).
During remote start, the heated seats can turn on by pressing the button. So what I do is tap off the 12V power on the one side of the heated seat pushbutton to power the circuit and use a relay to send that same 12V to the other side of the pushbutton. Since accessory voltage doesn’t exist when the car is remote started, I will use that as well so that the relay only turns on when the car is remote started instead of a normal key start.
When the circuit is powered up it will wait 8 seconds (to allow car to fully start and voltages to stabilize). The accessory voltage is read by a Picaxe-08M micro-controller. If it is not there, the micro-controller will pulse the relay to simulate a button push. If the accessory power is there, that mean the car was started by the key and the micro-controller will do nothing.
Two physical switches are used to disable part or all of the circuit. One will disable the passenger heated seat and the other disables the entire circuit. Can’t wait to install this in my car! It’ll be nice to warm up the seats at the same time as warming up the car.