I have a large amount of excess liquid tight non metallic conduit from a home rewiring project, I'm thinking about using it as a wiring path under the vehicle. I'd wrap the part in the engine bay for additional heat protection, though the conduit is 200+ rated.

Anyone think of a downside to this? I'd be passing the trailer wires and back battery cables.

 

Liquid-tight non-metallic duct (flex duct)...
Downsides... a tight conduit must not be tight but vented to dry any moisture that Murphy pours eventually in to corrode connectors.
Passing wires with their connectors bulk into a flex conduit may not fit.
Cutting and splicing wiring to make them fit is senseless.
How would you handle wiring harness branching ?
200F+ is peanuts to an exhaust nearby.
Cannot remember seeing reports that the stock wiring fails and needs such protection.

 

Not looking to replace stock wiring, but a more secure method of passing larger wires to the ck of the vehicle for towing, my trailer lines are installed and relatively safely routed, rear Anderson plug, and rear battery.
I doubt I'd bother except I have so much extra, and I can't think of any real downside. Each end would be in a water tight connector and wires would have cable glands.
Thank you for feedback. Just trying to think of potential downsides.

 

Two things to consider:
1) The current rating for household (AC) wiring is different that that of automotive (DC) wiring because household wiring has a much higher voltage (120 in the US) so it needs to draw less current for the same amount of power. For example, a 100 watt load through a household circuit only needs to draw 1.2 amps but that same 100 watt load through a 12V DC circuit needs to draw 8.3 amps. Since current capacity is a function of wire diameter what you will really want to know is the wire size (AWG) which you will then be able to use to look up the recommended amount of DC current you can safely draw through the wire. It may or may not be appropriate/worth it for your needs.
2) Be sure to put a decent breaker on the wire (maybe even two if its running to a rear battery) because it for some reason the protective insulation is compromised it will ground against the chassis and draw a TON of current which would be pretty dangerous.

 

In addition to whats been posted I would be concerned about vibration. It will cause the wires to chafe over time and is a guaranteed failure. I'd classify the chafing issue as an if not when and you wont know when it's going to strike. That is unless you inspect the wiring in said conduit visually by pulling your wires every once and a while.

 

I did this exact same thing to run a single 4ga conductor back to my rear interior fuse block through 1/2” water tight conduit. Depending on the size of the conduit you have you can run it far enough away from the exhaust for the heat to not be much of an issue. I’d recommend spiral wrapping the length of wire with tape to minimize chafing…like OEM harnesses have.