How do you get an amp power wire through the firewall?

[jwolk1]

I am installing an amplifier and would like to use an existing hole to put the power wire through the firewall. I have found 2 existing holes:

1. One hole is on the passenger side by the battery and is used for the wire that runs to the siren on the stock alarm. This is a perfect location (as it is on the correct side of the car), but I think the hole is too high on the fire wall as it looks like I need to remove the dash to get to it.

2. The second hole is on the driver’s side and is used to run several wires from the fuse box to the engine compartment. Although this is easy to get to, I would have to run the power wire behind my head unit which I believe will result in amplifier whine.

Any other suggestions for existing holes or insights? Thanks -

Jeremy
1983 Guards Red

[Obin Robinson]

don't drill down through the glovebox location because:

1) there's AC components in the way and you may F*** up your entire AC system.

2) there's a crapload of soundproofing and carpet in your way there.

the best place i've seen is to drill a hole on the area under and to the left (driver's side) of the steering wheel. drill it right through the firewall. first do a pilot hole to make sure no brake lines are in the way. you want to do this side because there's no hot exhaust manifold nearby. the power cable will snake from the battery tray, across the air intake plenum wall, and over to the driver's side. are you using really thick cable?

also remember to seal up the hole with a rubber grommet, and som RTV silicon sealant. SEAL IT UP TIGHTLY or you will get some very noxious fumes from the engine inside of your car.

there's other popular locations, among them being:

the holes left when gutting an AC system out of a car.

the battery tray area (be very careful about the AC system though).

the driver's side fusebox area (be careful about brake lines and other wires).

also, make sure that you secure the power cable in several areas so that it doesn't catch anything, or let anything get caught on it.

good luck!

obin

[minhpho]

On the pasanger side there is a big hole on my car (87 951) I think this is the one you are refering to 1. One hole is on the passenger side by the battery and is used for the wire that runs to the siren on the stock alarm. This is a perfect location (as it is on the correct side of the car), but I think the hole is too high on the fire wall as it looks like I need to remove the dash to get to it. You don't need to remove the whole dash, just the glovebox. HTH.

Minh

[ae1969]

I brought mine up through the fuse box...... drilled a hole on the side of the fuse box (metal).... placed a grommet....sealant.... and ran the cable to the battery......

[marksportcts]

I drilled a hole close to the battery, making sure that I was clear of wires under the dash. I just drilled in progressive steps. Do you know how difficult it is to feed a 1/0 gauge wire the size of a nickle thru a factory wire grommet? It is not easy.

[stray15]

You don't need to drill anything. Just run the wire right through were the speedo cable goes into the engine bay.

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Porsche, through and through
Tim
'83 944

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