Firewall?

[cornflakes 9]

For my next mini project, I'll be try using a 2 way radio as an "alerter" to notify me when the alarm goes off and I'm far away or in my home. (NOTE: I realize they now have smartphone car alarm apps that you can check on your smartphone and see the status of your car alarms system and it can notify you too, but I currently own or really need a smartphone right now).

The idea goes like this: One of the radios will be placed in my car, and the other radio with me. But the radio in the car will be plugged into an earphone/external mic wire. I want to place this microphone someplace safely in the engine compartment bay where my car alarm horn is also placed. Then the wire can go through the firewall and the plug will be inside the car so I can easily plug it into my radio when I'm going to use it, or unplug when I don't need to use it. When in use, they'll be set to VOX mode so that sound will transmitted only when noise is detected. It should be loud enough having the mic inside the engine bay where the actual alarm horn is.

My question is, how do you pass a wire through the firewall? Where is the place to do this? Is there any tutorial or video that shows how I can pass a wire or something thin through the car firewall (the lining that separates the inside of the car and the engine bay).

Thanks.

Oh, and I don't know if this will actually work. Theoretically i think it will work, but I won't know until I actually try it!

[Greg_E 211]

People with the automatic transmission have been passing wires through the rubber cover where the clutch would come through. If you have a manual car then the wires all go through about 6 to 8 inches higher on the firewall where the brake vacuum booster is located. You'll see a big bundle of wires and it should be covered in take and a big rubber boot. Unwrap the tape and feed the wire through the boot.

Edited September 6, 2014 by Greg_E

[cornflakes 9]

I'm still waiting to get the VOX earpiece/microphone so I haven't been able to test it out yet. I tested it out simply putting one radio in the car but when the car alarm went off, it wasn't loud enough for VOX to pick it up and transmit to me. I'm hoping that putting the mic through the firewall and into the engine bay will be loud enough for VOX to work.

If not, my back up plan will be to simply add a 2nd siren inside the cabin. Then I can just put the radio right next to it and that outta transmit the noise for sure lol.