Just got my first CB radio and saw in the instructions that I am to connect one wire to the + term of my battery and then attach the other wire to any exposed metal part. Maybe a PhD is required to explain to me how this will work since I've never gotten lightbulbs to work without having both wires touching the lightbulb.

This was in a Cobra 75WXST Installation manual.

I'm thinking this manual is B.S.

Any input from the experts?

 

look in the tech section. there are two writeups on this very cb. use the search feature too. there is extensive threads on this cb as well

 

The red wire with the fuse goes to the + the black wire goes to the the - which is the ground wire and toyotas along with most cars use the metal of the truck/car as the ground. That way you only have to run a power (+) wire to the device and gound to the nearest metal.

If you use two wires at the same point on a light bulb it won't work. But if you put one wire on one side of the filliment and the other wire on the other end of the filliment you have to made a circut and have light. If you look at the bottom of a standard 60 watt bulb the part that has the threads is one side of the filliment and the center of the base is the other.

So to recap for the radio to work, the electrons must flow in a circle: one wire to the radio, from the radio to the body, the body to the battery and again the battery to the radio. Leave out a part of the circut and the radio/light/motor can't work.

Also try to run your cb directly to the battery. You will have to remember to turn it off when you shut the car off but you will have a lot less "electrical noise" from the engine compartment.

As Bob said lots of good "how to's" in the tech section for installing that radio.

 

I saw the other writeups, but I was more interested in getting a reply as to how a circuit like this works. Thanks Poul D'eau for the explaination.

 

Glad I could help.

 

The basic answer is that in the vast majority of motor vehicles the chassis acts as the 'other wire'. You'll see a thick earth strap connecting the battery to the chassis or body of the vehicle, it's a much lower resistance conductor than any reasonable sized wire.

 

ah...always wondered what that extra strap on my battery was for! Thanks.