Ham Radio Install and Power Wiring Questions

[bbianchi]

So theres several threads but none seem to address my two questions.

1) What have you that ran direct to the 12V battery found is the best path through the firewall (the more details the better)?

2) Has aonyone checked to see if the 12v Neg (-) on the Cig. Lighter is keyed to the ignition? I would really love to accomplish having the 12v + from the batt. and the 12v neg to the Cig. Lighter if it is keyed so that when the car turns off my circuit breaks and the radio is forced to shut off.

Thanks!
.Brandon

[GeoGeek]

<div class='quotetop'>QUOTE(bbianchi @ Oct 18 2006, 07:26 PM) [snapback]334821[/snapback]</div>

So theres several threads but none seem to address my two questions.

1) What have you that ran direct to the 12V battery found is the best path through the firewall (the more details the better)?

2) Has aonyone checked to see if the 12v Neg (-) on the Cig. Lighter is keyed to the ignition? I would really love to accomplish having the 12v + from the batt. and the 12v neg to the Cig. Lighter if it is keyed so that when the car turns off my circuit breaks and the radio is forced to shut off.

Thanks!
.Brandon
[/b]

If you need to run the +12V directly from the battery, then I'm assuming it's because the equipment you have in mind has a substantial current draw (i.e. more than the 10amps or so you can pull from the cigarette lighter-style outlets in the car)....if not, that's another story, disregard the following.
To answer your question, I believe that it's the +12V wire going to the lighter plug(s) that is switched power (not the ground). Also, the 12Volt battery is actually mounted in the right rear corner of the car (behind the right rear wheel well under a cover piece), so you don't need to go through the fire wall to get to a +12V source.
My recommendation would be to ground your equipment to a chasis ground as near as possible to the piece of equipment; then come off the battery (with +12v) into a fuse then into a relay and out to your equipment.
You can use the same switched power wire that goes to the radio to trip the relay if you want or you could have it wired to a toggle switch you can switch from up front manually.
Hope this helps.

[bbianchi]

I honestly had no idea the 12v battery was in the rear right. I assumed it was front left... HAH!! No wonder people ask how to take the cover off so much... now I need to go read that thread.

I guess the relay idea to the +12v off the cig is a good idea. Any pointers on the relay type and potential retail locations? IE. Radio shack?

Thanks
.Brandon

[GeoGeek]

<div class='quotetop'>QUOTE(bbianchi @ Oct 20 2006, 01:11 AM) [snapback]335420[/snapback]</div>

I honestly had no idea the 12v battery was in the rear right. I assumed it was front left... HAH!! No wonder people ask how to take the cover off so much... now I need to go read that thread.

I guess the relay idea to the +12v off the cig is a good idea. Any pointers on the relay type and potential retail locations? IE. Radio shack?

Thanks
.Brandon
[/b]

Any good Car Audio shop that does car alarm installs should have the supplies on hand.
You will need:
1.) a relay....preferrably one that has the wiring plug included...Bosch is a good name.
2.) an in-line fuse & fuse holder rated to handle the current load you plan on drawing (eg 15A)
3.) Enough wire to run from the battery to wherever you need it in the car (gauge depends on
load.....eg 12-gauge)
4.) Enough switch wire to go from radio/toggle switch to the relay location.
5.) Various crimp on terminals & connectors.

Again, this is all unecessary if your device can be adequately powered using one of the cigarette lighter plugs already in the car. I don't know what kind of current load a Ham radio transmitter/receiver pulls, so
I can't say for sure. If it does exceed the capacity of the cigarette lighter plugs in the car, then the switched relay and direct power wire to the accessory 12-volt battery is probably the way to go.

Regards

[glenhead]

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