I plan on mounting the bottle between the rear seats and was wondering if there would be any reason not to use existing wiring that I have back there.

I have a power distribution block and one for ground that I can tap into to get my 12v source. I also have the switched source for the amps that I could use for my switched 12v. The only thing then would be to run both to a relay and hook up the bottle heater to a switch right?

The wire going to the trunk is 4ga and using an inline 120amp fuse at the battery. I assume I wouldn't need to refuse anything or if I did it would happen in the trunk maybe???

I don't really want to run any extra wires if not necessary.

Thoughts or opinions?

 

Just tie main power into your 4ga wire to the relay. Then relay to heater.. other side of heater to good ground. take one side of the coil on the relay pin85 tie it to that ground. only thing left, is switched power to the relay coil pin 86.
and your good.
Ricky

 

Yes, NxRicky is right again that is the only wire I would reuse.