I got a 4 guage power wire I need to get through the firewall. Is it better to run it through the passenger side or driver side?

 

Actually on the passenger side under the battery tray is a grommet that covers a hole that you can run the wire through.

 

 

Great thanks man

 

I put a starter in a civic that used that location.

the guy just removed the gromment completly, and then ran his 0 ga through the hole. The top of the wire had rubbed so much that the wire was exposed. The firewall had burn marks on it where the wire was shorting out on it.... oh ya, and there was no fuse at the battery on that wire either. yikes!

 

It's good to use some split loom tubing on the cable where it goes through the firewall.

 

Or slice the grommet and run the wire through it to make a perfect fit.

 

thats what I did...spliced it in the middle...pushed the wire thru the piece and put a ring of silicone around it just for added protection in case of a leak

 

Same thing here. Split the gromett and ran 0 awg throguh.

 

Split loom won't do anything to protect your wire...the only correct way is to use a grommet. You could also purchase a waterproof grommet from a manufacturer like stinger.

 

Why would you say that split loom won't protect the cable? Sounds like candidate for some testing. Hmm, 2 layers of material, or just 1 layer...

My firewall grommet was missing altogether. So i use it. The edges of that hole are not sharp. I'm rather confident that split loom is indeed more protection than just the cable insulation. Gee whiz, why do you think the factory uses it all over the car's electrical system. It's to prevent the wires insulation from rubbing through. That's what it's made for, not just for looks.

 

In comparison to a grommet I don't think it would protect as well.

 

I think a grommet is the best.
Split loom in to the car throught the gromment is redundant, but it wouldnt hurt so go for it. I've seen a lot of cars with missing grommets, split loom and lots of tape for those ones.

I like to melt grommets with my iron << for poking the hole >>, instead of cutting them with a blade. I think it makes a better waterseal.