RX8Club.com - Best Way To Get Wires Through Firewall?

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Quote:

Originally Posted by Socket7 (Post 2923003)

I went through the main wiring harness grommet. It was a bit nervewracking but it's the only place that will let you fit very thick wires through the firewall without taking a drill to the car.

i did this today and ended up cutting 5 main harness wires. my car will no longer start.. called mazda dealership and it will be 5,000+ to replaced wire harness with labor8(

no one try this!!!!

Pshhh for 5k... I'd do my best to splice them back together. Even if I can't get a soldering gun in there.... slide heatshrink on em, twist the ends, shrink, and let er eat.

Worse comes to worse.. extend both ends of the wires on both sides of the firewall, drill a new hole and pass the wires through there. Just bypass the harness. Might be the best idea actually...

Quote:

Originally Posted by bobsaggit (Post 3969554)

i did this today and ended up cutting 5 main harness wires. my car will no longer start.. called mazda dealership and it will be 5,000+ to replaced wire harness with labor8(

no one try this!!!!

Thats why you always start from the inside, start at the lowest corner farthest away from the wire bundle, and pierce at an angle down and away from the harness....

sorry to hear that you cut your harness

i did do it from inside the car and amed away but behind the wall the wires bend into the path. i only ended up cutting 1 wire and it was the wire that tell the car the clutch is pressed. i soilderd the wire then heat shrank them and is all better.

I avoided a lot of problems by using a Class-D sub amplifier. It's vastly more efficient than Class AB's which are the usual. As a consequence, 10 ga wire is fine, and that fits through the taped over hole through the firewall a few inches toward the outside from the washer tank. The 10 ga also fits into the clips already built into the cable trays under the scuff plates.

http://www.woofersetc.com/p-7512-kac...amplifier.aspx

21A max current draw.

http://cgi.ebay.com/Stinger-Wire-4-G...item48404944ce

I would recommend drilling a hole and using one of these.

If your wire gets dry forget the lubes, just spit on it and keep on tugging. lmao

Seriously the grommets above work great.

Quote:

Originally Posted by LunchboxCritter (Post 3980000)

If your wire gets dry forget the lubes, just spit on it and keep on tugging. lmao

As funny as it sounds, this is really one of the best options I've used. DO NOT use WD-40 or similar lubricant to help you pull wire through anywhere in the car. It will break down the insulation on your wire. Use spit or water. Works like a charm.

And the grommets linked really are THE PERFECT item to use.:icon_tup:

Quote:

Originally Posted by bobsaggit (Post 3969554)

i did this today and ended up cutting 5 main harness wires. my car will no longer start.. called mazda dealership and it will be 5,000+ to replaced wire harness with labor8(

no one try this!!!!

I'll give you $4,000 for your car the way it sits, since it's going to cost $5,000+ to fix it. :)

Or you can give me $3000 and I'll fly up there and fix it for you. :)

Thru Firewall without drilling....

Quote:

Originally Posted by mikeschaefer (Post 2924037)

There's already a hole between the washer fluid tank and the passenger side fender. It's just hidden with tape that is stuck from the inside and painted the same color as the body. The hole is an oval. All you need to do is poke a hole in the tape, put a rubber grommet in it, put some dish soap on your wire and then run it through.
I wouldn't use oil or WD-40, they attract dirt and won't dry up like dish soap. Next time I'm going to try KY since it's water-based.

BTW, from that hole the wire comes out behind the passenger kick panel, which you'll need to remove. But that's easy.

Read the above post and had to check it out. Really liked the idea of a NO DRILL method.

I installed a vaccum / boost line for my GOODbox. I found the described oval hole on the passenger side of the engine bay. From the engine bay side I pushed a wire (e.g. coat hanger) thru to the passenger side foot well area after the kick panel was removed. I then used electrical tape to attach a hose to the wire and pulled the wire & hose from the foot well into the engine bay. Dish soap was helpful.

Took photos of this OVAL hole for the NO DRILL method. See the attached pictures with arrows and lines. Shot photos from the engine bay fire wall and from the passenger side foot well with the kick panel removed.

What is not shown is the grommet that I installed afterwards.

The last two foot well pictures show the coat hanger with hose taped to it, just prior to pulling into the engine bay (between the red lines).

Hope the photos help.