I'm ready to wire my CB radio into my truck and just have a quick question. I have been told by some people that I should tap into the "hot" side of the fuse for my power. Now I have also heard people say to use the "cold or dead" side of the fuse. Which should I use?

To me, it would make sense to use the cold side because then you are protected by the fuse. But I'm not really sure.

And the CB has inline fuses on the power wire so that should be good enough protection right? I shouldnt have to put an inline fuse right at the block also should I?

Thanks alot.

 

Putting a splice connector at the power wire for the cig lighter may work good in your situation, and the cig lighter power is protected by a fuse as well, and should hold the current demand for the radio. This way you won't have to mess with tapping in right at the fuse box.

 

If you're going to piggy-back a fuse in the fuse box, use the cold side to prevent overloading the wiring on the hot side.

Personally, for a CB, I prefer to run direct from the battery to reduce the interference through the system. It seems to help more in some vehicles than others.

-Joe

 

I thought about the battery also, but I want my CB to turn on and off with my ignition. And my CB has two power wires, one for constant power and one for "key on" power. They both need to be plugged in, so I would need to use a fuse for the key on power anyway.

And do you think that I could get sufficient power from splicing into the powerpoint?

 

Yes, you will have plenty of power from the power point as it's rated for 20A. However, it's hot all the time. You'll still need a switched source for it as well. I suspect the switched source acts as an on-off trigger for the main power source. If so, I'd run the power direct from the battery and pull a switched source from something nearby (the switched stereo power wire works well for this and is easy to find).

Just depends how the radio is wired.... Dare I ask what kind of Radio it is?

-Joe

 

It is a cobra, 18 WXSTII. I have heard lots of good things about it.

I am thinking that I will run the constant power and the switched power wires both to the interior fuse block and tap into the cold side of each fuse for the power. Do you think that this will work just as well as splicing into the powerpoint wire?

Thanks again.

 

Yes and no.... it will work, but in my opinion, it will not work as well as running the main power lead direct from the battery. The battery will act like a big noise supressor and should help reduce the noise in the power feed. It makes a huge difference in some vehicles, almost no difference in others. But yes, any power source for it will work.

-Joe

 

Ok thanks, I will try running both to the fuse block, and if there is any noise interference I will run the constant power lead straight to the battery. So if I add on a length of wire to run to the battery, would you recommend fusing it right at the battery also? Sort of like you would with a car stereo amp?

And is it possible to overload the fuse block? Just thinking because I have an amp turn on wire running to my radio fuse, then with my CB I would be running to 2 other fuses. I am guessing it should be fine since the CB only draws 2 or 3 amps but then again, I don't know a whole lot about electrical.

 

As long as you're pulling any additional current for the accessory through the existing fuse, there should be no problem. (I've been assuming all along that by 'cold side' you meant that if you pull the fuse out and check, the side that's 'dead' or 'fed BY the fuse'). You want to use the existing fuse to protect the existing wiring from overload.

The amp turn-on wire is essentially a switched input, correct? If so, you could just piggyback the switched feed for the CB onto that one as well. Again, I highly doubt it's using it as any more than a simple switched input. The main power feed is most likely the other main power wire.

Indeed, if you run it direct from the battery, I would place another fuse as close as possible to the battery to protect the wiring.

-Joe

 

So basically, you are saying that if I am only running the CB (2 or 3 amps max) that it is fine to pull current through the existing fuse in the block? The wipers fuse is 30 amps and that is what I was planning to use for the key on power wire. As for the constant power wire, should I tap the same size fuse?

 

I installed the CB today and for my constant power, I used the 15 amp fuse for turn signals and etc... Will this be ok? I mean will it have sufficient power?

 

Steve, use the cigarrete lighter socket and a plug, have it handy and over with but keep the CB fuse in line.
Hooking up to other fuses that run other things is inviting noise when they operate such as the clicks from the turn signals and whine from the wipers etc.
The CB is AM radio, it picks up all kinds of trash that you don't want to make worse.