Ham Radio Install and Power Wiring Questions

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

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.

 

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

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

 

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