Heated steering wheel retrofit?

it gets cold up here in new england, and it'll be especially cold this winter...



has anyone attempted to retrofit a heated steering wheel in before?

i dont know if its a simple swap where you just

-swap steering wheel

-swap steering column trim for one with the heated wheel button on it

-wire it up to some 12v source in the steering column



or if it ties into the entire HVAC system or some weird crap



does anyone have a wiring diagram somewhere? or schedumatics?

:help: