Routing wire from starter battery to house battery

[joshik]

I am planning to run some heavy awg wire from my engine bay to my house battery in the rear cargo area (area where sub used to be). I have a Renogy DC DC charge controller back there w my house battery. I'm trying to decide if I should run wire from the engine bay thru the firewall along the door trim to the back or run it on the outside by the frame (tucked away) and come up through the running board light grommet.

Thoughts? Anything wrong w running it inside the entire length? I'll be charging at 40amps. I will of course have the proper safety measures. Proper fuses. Correct awg wire. Etc.

 

[Berty_K]

Ran through the firewall to a DCDC charger. There a grommet on the driverside. Didn’t like the idea of heavy gauge wire exploited to the elements/potential road debris

 

[joshik]

Ran through the firewall to a DCDC charger. There a grommet on the driverside. Didn’t like the idea of heavy gauge wire exploited to the elements/potential road debris

yeh i thought of the debris and stuff too but i figured tucked up and out of the way with some sheath would be pretty good.

Running it inside seems easier though.