I need to pass a few wires through the firewall. Upon initial observation I couldn't find any easy accessible holes. I was wondering if anyone has had some success in passing wires through the firewall.

I'm hoping that I don't have to drill a hole.

Thanks
Mark F

 

I had to pass a 2 guage wire from my battery to a fuse box inside the car for a couple of amps. I used the clutch cable opening. To access it, you have to pull the splash guard inside the driver's side wheel well off, or at least back. There's a rubber cap surrounding the cable and I passed the cable between the surround's outer edge and the hole that it seals. There is a bit of access room above this hole leading to the engine bay. When you pull off the splash guard, open the hood and look for light coming in. It took a little fishing, but it's not terribly difficult. Just make sure to push the plug back in the hole as much as you can. It should seal the hole fairly well, even with the wire(s) passing through. Hope this helps.

 

That definatly helps that was the type of info I was looking for. How much in diameter do you think I get through there? I need to pass a bunch of wires, probably almost 1" diameter.

Thanks
Mark F

 

My advice on running wires through the firewall is to buy a water-proof grommet from a car audio store. I have used the ones made by phoenix gold. These grommets screw down to make a water tight seal. They usually run 4-6 dollars and are worth every penny, it makes adding additional wiring simple and avoids ruining the factory seals around various cables and harnesses.

 

I only had to put the 2 guage wire through the hole, but that's still a pretty large piece of cable. It's a big hole, so you can get a good bit through there, but the more you put in, the more exposed that hole is to the outside, because you interfere with the plug's seal of the hole. Waterproof grommets are a good idea as well, but if they're what I think they are, you have to drill a hole. As far as ruining factory seals - what I've described doesn't ruin the seal, it just pushes it aside. By the way, this area is already fairly well protected from the elements as it is. Pull off the splash guard and you'll see what I mean. Are all of the wires you're running positive leads? If they are, you might consider running a single (big) cable to a distribution block inside the car. That way you can fuse protect whatever you're powering and simplify the install at the same time (not to mention protect the distro block from the elements. Good luck.

 

Interesting idea about a supplimental internal fuse block, which I happen to have sitting on my work bench. However, I need to pass a bunch of wires through. I need power coming in, but I have speaker, strobe and other wires going out.

I'm an Volunteer EMT and I'm wiring up my Max with lights and sirens.

I'll look into the speaker shop grommet. Unfortunately that will require me to drill a nice sized hole somewhere on the firewall.

Any online sources for the grommet?

Thanks

 

I've wired up a few Nissans (200SX, Frontier, Maxima), and I've never needed the grommet because I've always used the clutch cable hole, so I don't know where you'd find something online. When I'm completely without a clue (usual state of affairs), I try a search at www.google.com.

 

I'll check how much room there is in there, when I get a chance. Is the gap caused by pushing the wires something than can be sealed with silicone/urethane? Or should I keep that stuff away from there?

Thanks

 

I've never sealed up the gap because it's fairly well hidden from the elements, especially with the hood down and it's also not a very big gap once you press as much of the boot back in as you can. If it would make you feel better to do so, I say go for it, but I really think it would be overkill. You'll see what I'm talking about once you get in there. Also - it usually takes a bit of elbow grease to get that boot in and out. Take care not to rip, tear, or otherwise molest it. The cool thing about doing this is, as I recently found, you can take the $150 worth of Phoenix Gold wiring back out when you sell the car, and seal up the hole just as the little design guys at Nissan had planned. No one will be the wiser. You'll have to post some pics of the end result of this.