Stereo upgrade wiring question

[phil2273]

I'm adding a amplifier to my stereo on my 71 Mach 1 that requires the amp to be directly wired to the battery (8 awg wire with in-line fuse). If others have done this, what is the best way to run the amp wire to the battery through the firewall. It has the original wiring harness. The wiring harness goes through a grommet at the firewall, but not sure if I can or should try to run the wire through the existing firewall grommet that the wiring harness goes through or do a new penetration through the firewall. thanks for advice in advance.

 

[giantpune]

Where are you mounting the amp? There are plenty of rubber body plugs all over the car. I would try to pick one of those to get the wire from outside to inside. That way you haven't added any new holes. If you ever want to undo it, a new rubber plug is $1.99.

 

[phil2273]

Where are you mounting the amp? There are plenty of rubber body plugs all over the car. I would try to pick one of those to get the wire from outside to inside. That way you haven't added any new holes. If you ever want to undo it, a new rubber plug is $1.99.

Mounting inside the glove box. The app wire is 17' long so I should have plenty of length. Sorry to ask, but where should I look for the body plugs.

 

[giantpune]

The plugs are mostly down low where water would collect. Like in the floors and in the sides of the trunk. Most people put their amps in the trunk, so I'd have plenty to chose from back there.

If you want to get from the battery to inside behind the glove box, maybe open the passenger door and look how the antenna wire comes in. Should be a rubber grommet there with enough extra room to poke a hole and run another wire. Then you can run your wire either under the hood and under the top corner of the fender, or run it the first length under the fender to get from the battery to that grommet.

 

[phil2273]

The plugs are mostly down low where water would collect. Like in the floors and in the sides of the trunk. Most people put their amps in the trunk, so I'd have plenty to chose from back there.

If you want to get from the battery to inside behind the glove box, maybe open the passenger door and look how the antenna wire comes in. Should be a rubber grommet there with enough extra room to poke a hole and run another wire. Then you can run your wire either under the hood and under the top corner of the fender, or run it the first length under the fender to get from the battery to that grommet.

Great advice. Did a quick inspection and pretty sure the antenna opening is going to work. Will be able to run inside the top and come out an existing opening of the engine compartment. Thanks so much.

 

[MaddMike]

My amp is in the trunk. I ran the power wire from the trunk, around the over the rear wheel-well, thru the rocker panel under the scuff plate, thru the footwell behind the plastic kick panel and then through the firewall with the other wires. The Amp is thin enough that even with the dorr open/down it doesn't hit the trunk floor hump. And... nevermind that flux capacitor. I had a trunk mounted CD player and removed it, but had the space and didn't know what to do with it. It gets a good laugh at car shows. I also custom cut Masonite panels and put them on both sides although the passenger side should be open.

 

[tony-muscle]

As an alternative, depending how big your amp is, consider testing the passenger kick panel area. There is space there that may work. That's where I have my subwoofer. With that you don't need to take the glovebox space.

 

[Hemikiller]

You could pop a hole through the firewall where the AC vacuum hoses would come through. There will be a dimple centered behind the engine, under the cowl lip. I used it for the leads for my mechanical gauges and tach lead from the MSD.

 

[clevelandcoupe]

I snaked my amp wire through the speedo cable grommet.
Thanks, Jay

 

[phil2273]

Thanks for all the options. Here in the mid-west it's too hot to work on this week. I'll get back at it this weekend when it cools off.

 

[phil2273]

This is a great forum and wanted to let this group know routing the 8 awg amp wire through the antenna opening/grommet (recommended by giantpune) worked well and I recommend to others, even if you're putting the amp in the trunk. Was able to pull out the antenna grommet out, route the amp wire through that grommet and put the grommet back in place. I installed a new radio from Custom Autosound that I really like - bluetooth, pre-out, mic, etc. - all the features I wanted and looks relatively OEM. Rockford Fosgate PBR400x4d amp and Kenwood Excelon 6x9 in the rear deck and Kenwood 4x10 in the doors. Very happy with the sound.