[PCH]

Had few pics from when i was installing Optima in the rear storage compartment, so here is one of the ways to run battery cable through the firewall to the back. If needing to power an Amp or air compressor or adding extra battery, this may help:

Pull the passenger side wiring harness grommet from the firewall and cut off the tip from one of the pull tabs. Its a double walled grommet, so to feed the string or a wire installation tool to the other side you will need to puncture all the way through:



After few attempts the string will fall from behind the climate control unit:



Tie the string to the wire and pull through the grommet:



Gauge 4 is thick enough to handle all the load and still fits through the tab:





I put the wire inside the heater hose which makes it possible to just wedge it between the black cowl tray and the firewall. Use WD-40 or talc powder to feed the wire inside the hose:



There is plenty of room below the step guards to run the cable:



I put it inside the heater hose for extra safety:



All the way back. Takes about 16ft of wire to go this route:



Have been running my battery this way with no problems:

[SAKURA]

never seems to amaze me, always clean, ingenious work of art.
i like the extra care with hose installed.

good job

[litos_2006]

another great DIY by PCH can you say rep points

[PCH]

Thanks I've been in a nasty side impact accident years ago in another car that had the same mod and i'm glad i had taken extra time with pulling the cable inside the hose. That would have been one nasty electrical short

Also here is a convenient and reliable body ground connection point in that area - the bolt for the rear seat brace:

[mikesbluexb]

Thats killer, the battery fits perfect in there.

[bB626]

just saw this thread. great work!!!

[beanzermin]

what are you gonna do about the ugly whole in the engine compartment now?

[PCH]

It's been like that for so long, doesn't look ugly anymore

[squirrel]

Very nice!!!!!!!

THANKS!

[ScottyTuned]

This may sound dumb, but what does the connection in the engine bay look like at the fuse box/red piece? Do you just clip that onto the power wire you ran? Also, is that 4 gauage or 0 gauge?

[PCH]

It's a 4 Gauge. I just bolted the stock terminal and the cable that i added together using the power post like this:

[beanzermin]

while your at it, why dont you wire tuck everything? make it look like a clean V-Dub.

[PCH]

They have, like 5 wires in the engine bay

[Mini_UAV]

Can you post what model Optima that is? Also what battery bracket are you using to hold it down. I love this mod and want to know exactly what I need to do it the same way. Keep up the good work and great DIY's.

[PCH]

Thanks! Its a 51 Series Optima for Civics etc. Here is the original thread with bracket info: Battery relocated