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Wiring Through Corolla Firewall

j-d
Explorer II
Explorer II
Working through making wife's 2006 Corolla towable. Now I need to get the Power and Breakaway wiring for the Brake Buddy through the firewall from engine compartment to cabin. Wondered if somebody'd found a spot to poke through. As cars get newer, access seems harder to find. And even less places to drill a hole!

Also, I'm adding surface mount LED Stop/Tail/Turn lights between the bottom of the tail lights and the top of the bumper fascia. I think I can find a way to fish wiring down to under the car where I can run it forward. Anybody got tips for that? It'd be easy with the bumper fascia off, but I'm hoping to avoid that.

THANKS!!!
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB
5 REPLIES 5

j-d
Explorer II
Explorer II
I found a main harness grommet near the passenger side strut tower. Can be felt but not seen from inside when the glove box is out. Just got my wiring fished through there late yesterday. Project moving forward.

Thanks everybody!
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB

DSDP_Don
Explorer
Explorer
If you look at the firewall, there are typically 1-3 spots that you can feed wire through. Often, around the wiring harness, or the steering column or even the brake booster, there will be a rubber boot sealing the unit to the firewall. I usually use a sharp wire, poke through the rubber and pull your wiring through. Once done, you can place some silicon around the puncture.
Don & Mary
2019 Newmar Dutch Star 4018 - All Electric
2019 Ford Raptor Crew Cab

j-d
Explorer II
Explorer II
Will look into both options.

Thanks for the door post reminder. I actually just did that on our E450 coach cab when I had to run a new vacuum hose. Hadn't thought of it for the Corolla.

Will look at the door too.

I've gone with the main harness grommet on other vehicles, and when I recently did my Nissan pickup I used the A/C condensate drain grommet.

Thanks again, Case Pends...
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB

drcook
Explorer
Explorer
there will be a spot where the main wiring harness enters the cabin. there should be enough room there to slip another wire through. that is where I brought the wiring through to communicate with the extra computer boxes I added to my pickup truck

just make sure you don't tear any rubber seals that the mfg put there to keep out weather, protect the edges of wires from sharp edges, etc
2004.5 2500HD CCSB Duramax/Allison - was an Overheater fixed it!!! Bilsteins, Banks stuff, Hellwig Sway bars front and back
2010 Crossroads Cruiser 30QBX

2 Doberman/Rhodesian Ridgeback Crosses - brothers
2 Beagles
1 Shih Poo
1 Shih Tzu
1 Camping Cat
1 wife

TwoPines
Explorer
Explorer
I had a similar question a while back, but for a PT Cruiser. Someone mentioned simply routing the wiring through the door opening and that is what I ended up doing because there didn't seem to be a good spot for drilling through the firewall. I brought the wires inside on the passenger side of the car. Under the hood, I used wire ties along with some sponge insulation to keep the wiring in place. There was a small gap in the metal where the hood met the fender, so that's where I tucked in the wire, holding it in place with the sponge rubber. I brought the wires inside near the bottom of the glove box and shoved the wiring behind the plastic molding where it meets the carpeting and then under the floor mat. I had just enough length in the break-away wires to reach the Brake Buddy. I ran the wiring inside the PT Cruiser in a similar fashion to the back end for the magnetic-mount tail lights. I still need to make a couple of steel brackets for the magnets to lock on to.

Before settling on this route, I figured it would be easier to drill from the exterior of the car into the interior as I would be less likely to hit something in the engine compartment.