Questions About Wiring in a CB Radio

JSMcustoms · Mar 19, 2013

I just got a new to me Cobra 25LTD Classic CB radio. This is my second CB, but my first was not hardwired into my vehicle like I intend to do with this one. However, I'm a bit confused as to the best way to wire it into my vehicle's electrical system (2005 Jeep Grand Cherokee). I've heard of people tying it into the fuse box for power off of an existing fuse or adding a new one just for the radio (or splicing into a hot wire coming off the fuse box). In my case, my CB has an inline fuse on the power wire and I was wondering if it's a good idea to just run this straight to the battery seeing as the power circuit for the radio is fuse protected and just grounding it to one of the vehicle's chassis grounds. Do you guys have any better ideas?

theHobbyist · Mar 21, 2013

I actually had one of these a while ago... Anyways, I've always tied into the fuse box when I could so I can ditch the inline... It's a bit more of a pain but worth it IMO. If you're worried about it being on switch power or not, you should be able to find a constant hot lead there. I never did like tying off of another hot lead, you run the risk of overloading the circuit, a small risk but a risk none the less. And if memory serves, since most of it is analog it's a 2 wire system not a 3. That makes getting power to the unit easy. All you have to do is decide if you want power on the or off the switch.

Another path you can take, if you don't use your cigarette lighter is to yank the power out of the back of that... Never had Jeep so I can't tell you if it's on or off the switch.

Have fun with that thing...

SpookStrickland · Mar 21, 2013

I would wire it up straight off of the battery. I would put a fuse as close to the battery side as possible so if you ever get a short because if you have a fuse close to the radio, if the wire gets cut or scrapped anywhere between the fuse and the battery you are going to have a serious melt down.

gadgetgeek · Mar 23, 2013

Depends on if your radio needs constant charge, or how much it will pull on standby. I'd find a switched hot accessory circuit. unless you got all the options, you should have one. and I'd keep the inline fuse, more is better, and you never want to track down a burnt wire somewhere in a modern cars dash. and never never tie into the yellow wires, thats the self destruct system.

JSMcustoms · Mar 23, 2013

I ended up wiring it straight off the battery and I've only got one fuse in it (closer to the radio than the battery). I need to move that back at some point, but I don't think the wires are any place they could get damaged. Inside the inline fuse holder I have a 10 amp fuse as it's the only thing I had laying around. Should I drop this down to a 5 amp?

gadgetgeek · Mar 24, 2013

I would go with the minimum required for the draw of the radio. no idea what that would be, the mfg should have a recommendation. 10 seems high, but, I dunno. if you can find a fire-wall grommet to run the wires through, that would be great. you might not crimp them, but someone else might, and that would ruin a trip. I've seen it happen on work trucks.

JSMcustoms · Mar 24, 2013

It draws around 2 - 5 amps. Running at full load, I'd expect it to blow a 5 amp fuse (possibly). Going to get a 5 amp fuse for it when I go into town tomorrow and put it in just to see how it goes. I tried looking for the firewall grommets, but it looks like you have to pull the dash to get to them (hidden quite well on 2005 Grand Cherokees). :/

SuzukiGS750EZ · Mar 25, 2013

Look behind the pedals. Pull some carpet back. I've done a ton of audio installs, and most of the time there is a rubber grommet. Doesn't matter if wires are coming through them, those are usually the ones i use. Just poke a tiny hole next to the wire cluster and feed through. If it bothers you a lot, put some silicone to seal it.

ChrisY · Mar 26, 2013

I use cigarette lighter plugs for my CB. Makes for a neat installation especially if the outlet is somewhat hidden. It also powers off with the ignition. If you must hard wire to the battery there are no issues. Just make sure you use 14 or 16 gauge wiring along with the inline fuse. The benefit of hard wiring is that it reduces engine noise.

RobKevlar · Mar 26, 2013

You did it right except for the wire routing. Like someone else said there are several options to run the wires through the firewall. Also you should just run your ground wire (Black) to a rounding point close to the CB. The long ground wire youhave now will open your audio quality up to more interferance.

JSMcustoms · Mar 27, 2013

Interestingly, I barely have to turn the squelch knob at all to get rid of the background interference (set just barely above the off mark for the power/volume control). I'll look to see where I can find a grommet when it's not below 30 degrees out, though I think the only one I'm going to be able to get to without pulling stuff a part big time is the one for the steering column (not sure where this comes out in relation to the engine etc without looking. no good if too close to anything hot).

bacpacker · Mar 28, 2013

I have been wiring in Ham Radios for several years. I always run the wires from the battery. I also place the fuse holders in both hot and ground leads, as close to the battery as possible. If your radio says it will draw 5 amps at high power, I would use a 6a or 7.5a fuse. Slightly more than the draw. That will let you run high power, but still protect everything. I do not like running off the cigarette lighter socket wiring. I've found it to be too small a gauge wire for what I trust. I use a 12ga most of the time, but wouldn't go smaller than a 14ga wire. In most cases running from the battery to the radio, you will be running 10-15' of wire. Too small of a gauge wire could heat up and burn. Just my .02.

Running the wires into the cab is alway a PITA to me, but usually you can find a wire bundle, or something that runs into the cab and just feed you power in beside it. A little silicon will seal it back up if needed.