The ABCs of CB Installation
All you need to know to change out a citizens band radio and stay loud and clear.
Without a citizens band radio to stay in touch with drivers around you on the highway, the road would be a lonely place. Conversation can make the miles speed by, not to mention all the valuable information you can get about traffic and road conditions.
If you don’t have a CB, need to replace a broken CB or want to upgrade to a fancier model, all you need are a few simple tools and the ABCs of swapping or installing one to save you money.
When you go to buy a CB, do your homework. “Buy one that’s really to your liking,” says Ramon Sandoval, product manager for CB radios at Cobra Electronics. “Do a careful brand and product analysis, and look carefully at all the features.”
One feature that can be helpful (if you’re electronically capable) during installation is an SWR (“standing wave ratio”) meter. While an external meter can be used, having one on the CB makes it easier to match the setting of the antenna to the radio so the outgoing signal will be properly distributed when you transmit.
Another consideration with some CBs is the polarity of your truck’s electrical system – whether it has a positive or a negative ground. According to the installation manual for a Midland Model 4001 CB radio, the unit is designed for 12-volt, negative ground systems only, and “some newer large trucks may have a positive ground.” The manual makes clear what you probably already know: If the minus (-) battery cable is connected to the engine block, the truck has a negative ground system. Check with your truck dealer if you can’t determine the polarity of the system.
Make sure your truck has a 12-volt system (not 24). If it has a positive ground system, you can purchase a CB designed for either type of polarity.
Mounting the unit
“Every CB comes with a bracket for mounting on the dash or in a cubby hole,” Sandoval says. “There will be a simple diagram to show you how to do that. You can also call our customer service line for help, if you need it.”
The manual for installing the Midland 4001 CB, for example, has some important advice about deciding where to install your CB: “Be sure that the unit is located so that it does not interfere with the driver, supplemental restraint systems (air bags) or impair access to any controls. Connecting cables must be routed and secured in such a manner as not to interfere with the operation of the brake, accelerator or other controls.” Although most trucks don’t have airbags, a few do, so recognize that possibility and ensure clearance accordingly.
Route everything carefully, use durable ties to keep cables in place, and then sit in the driver’s seat and make sure there is clearance everywhere around you – including your feet – before driving the truck. Make sure the front seat passenger won’t run into trouble, either.
Most units have a mounting bracket that makes it easy for you to attach it to the underside of the dash or anywhere else you want. The radio itself then attaches to the bracket at any angle you want.
- Attach the unit to the bracket, via the slide or hinge mechanism and knobs normally used, before installing the bracket. Then position the bracket on the dash or wherever you plan to mount it to make sure there is clearance for you when driving and that you can reach the controls. Brackets normally are attached with short machine or sheet metal screws, a type of screw that makes its own threads when a small hole is drilled through the metal first. Before starting the drilling, eyeball the length of the screws to make sure you have a good idea how far they will penetrate into the metal. Then check behind the metal panel where you will be mounting the unit to make sure there is plenty of clearance for the screws to go through without running into anything mounted there or damaging wiring or other components.
- Disconnect the unit from the bracket. Get an awl or sharp nail, and then position the bracket exactly where it will be when the unit is installed. When you are sure the bracket is in just the right place, hold it securely and stick the awl or nail through each of the mounting holes to mark exactly where they will go on the metal surface.
- Now you will need a drill that is slightly smaller than the diameter of the machine screws used for mounting. On Midland CBs, that means a drill that will make a 1/8-inch hole. Carefully drill holes right where your marks are so you can easily get the screws started in the metal. This will be easier to do right if you either use a hand drill and turn it slowly or use an electric drill that you can turn down to a low rpm. Be careful not to allow the drill to penetrate very far through the metal unless you know there is plenty of clearance.
- Finally, put the bracket in position. Take a minute to pick out exactly the right size and style of screwdriver for the screws because this will help make it easy to put enough torque on them without damaging the heads. Then install and snug up all the mounting screws.
Connecting the power wiring
On the Midland CB, connect the polarized power plug to the rear of the radio. If your radio has a similar, plug-in connector, connect it now.