Just posting for reference in case it might help someone else.
I located the rear glass defogger on my big horn. It’s a high current relay output. I tapped it to provide power to the heated glass I’m putting into my big horn non heated tow mirrors.
You take up the driver sill plate, pull up carpet and open the plastic carrier, and there are 2 harnesses. There is a heavier blue with white stripe. This is 12v when rear defogger is on.
I located the rear glass defogger on my big horn. It’s a high current relay output. I tapped it to provide power to the heated glass I’m putting into my big horn non heated tow mirrors.
You take up the driver sill plate, pull up carpet and open the plastic carrier, and there are 2 harnesses. There is a heavier blue with white stripe. This is 12v when rear defogger is on.