Hints and Tips for Mobile Installations

by Gary Saffer

The purpose of this document is to give the readers some ideas of what works for the do-it-yourself mobile installation of scanners, two way radios, and other mobile electronics. It is by no means all inclusive, and any suggestions, questions, ideas, or clarifications should be sent to me via the Strong Signals website. I plan to update this article with ideas, tips and hints from the readers as often as I can. I'll also add pictures as I get them.

Before you start to do a mobile installation, be sure that you have the requisite skills, patience, tools, and desire to do it. Installing your own electronic equipment can be lots of fun, or it can be an incredible pain in the backside. A lot of that depends on how well prepared you are to do the work yourself. Some installations are very simple; an example would be replacing your own in-dash stereo. However, if you are installing multiple scanners, a two way, a cell phone, speakers, antennae, and power wiring for all of them, the job will be complex and time consuming. I can't give an estimate, since the variables are so many, but figure 90 minutes per scanner or radio, including the antenna. I have spent more than one 10 hour day doing a complex installation. Be prepared.

I would like to thank Joe Conlon for reviewing this article and making very valuable suggestions to improve it.

The Disclaimer
This document is not meant to be an all inclusive tutorial. It is a collection of the knowledge that I have gained, some by making mistakes, over the past 25 years or so of doing mobile installation work on various types of radio equipment. The reader performs this type of work at their own risk. If you screw up, it's your problem (hence the previous paragraph). If you aren't handy with tools, familiar with vehicles and their electrical systems, comfortable removing vehicle components and parts ,then my advice is that you hire someone that is.

Let's Go
So, you have that nice new scanner, ham radio, CB radio or whatever and want to install it yourself. I've done a fair number of installations over the years, for myself and others, and I've learned a lot, had some fun, had some frustration, and even made a few dollars from it.

"Get the tools," as the Three Stooges used to say. There are some tools that are indispensable, some that are handy, and some that you don't need, but make the job a lot easier.

Here are the tools that I own and use for mobile installation. No, you can't borrow them! <G>

Essential Tools

Electric Drills

I have three. One regular corded drill, one cordless and a cordless right angle drill for getting into tight spots. You should have at least a corded 3/8" drill. Nothing fancy, just a variable speed, reversible model. You need drill bits too. An assortment up to ½ inch will do nicely.

Socket Set

At the very minimum a 3/8" drive standard set (metrics if you have a car that needs them). A ¼" "midget" set is also very handy. Actually, a good assortment of wrenches, socket sets, and other automotive tools will make your life much easier.

Soldering Iron

Just a standard one from RadioShack or similar. Essential for soldering wires and installing some types of coax connectors. Use good quality solder too.

Screw drivers

Although your drill can double as a screw driver with the proper bits, sometimes a hand held screw driver is what you need. Start with a #2 Phillips and a flat bladed screwdriver. Racheting handle versions are nice, but can be expensive. You may also find it handy to buy a kit with various bits such as Torx, Square Drive, Hex and other weird bits. Auto manufacturers use some of these bits for various components.

Wire Cutters.

Invest in a good pair. What's a good pair? That varies, but I like Snap On products. Expensive, but top of the line. For the more casual user, Sears sells some good tools under the Craftsman brand.

Vice Grips

Various sizes come in handy for holding items in place if you are working by your self. They can also be used to bend and shape brackets or pieces of metal that you would like to become brackets.

Crimper

There are various types, including those for wires and those for antenna connectors. In a pinch, if you are very careful, you can make vice grips work, but it takes practice. Some of them also come with wire strippers, which makes prepping wires much easier. Don't forget an assortment of crimp on connectors.

Wire Stripper

If your crimper doesn't have one, you will need a good quality wire stripper.

X-acto Knife.

These razor sharp knifes are so handy you just can't be without one.

Multi Meter.

Also known as a Volt Ohm Milliamp (VOM) Meter. Essential for checking connections, looking for ground wires, and checking for power on circuits. The cheap analog ones work pretty well, and are a lot cheaper than the digital ones, which you don't need for this king of work.. Also, a simple automotive test light is very handy for finding out if a potential power source is "hot".

Elecrical tape and heat shrink tubing.

Good quality tape is essential. Heat shrink tubing isn't essential, but makes the job easier and neater looking.

Wire Ties.

Various lengths.

Coat Hangers

The wire type. You can straighten them and use them for snaking wires through the vehicle. You can buy commercial snakes, but metal hangers work pretty well, especially for short runs.

Hammer

Not for those really frustrating jobs, but they do come in handy.

Ice Pick or Scratch Awl

For marking drill locations. Also, with the hammer you can punch through a starter hole for self tapping screws.

Tape Measure

You have to have one for measuring hole locations, making brackets and so on.

Hole Saw.

You can buy the generic kind at hardware stores. ¾" is very handy for drilling antenna holes and holes through the fire wall for running wires. There are also specialized antenna hole saws that make drilling antenna holes a breeze. Not only do they stop automatically, they burnish a nice ring around the hole for the mount to ground too.

Surgical Clamps

There are various sizes and shapes available. You can generally buy them at Ham Radio Flea markets. The stainless steel ones are good, but expensive. They are great for holding small wires while you solder them or holding other small parts while you work on them.

Machinists Spring Loaded Center Punch.

Used for marking drilling locations without having to use an Ice Pick and hammer.

Hook Tool

An automotive tool used for pulling dash board panels. Some people also use an automotive interior panel tool, which does much the same thing and is a bit less likely to scratch surfaces.

Flash Light

Good for seeing into those murky depths. I use one that can be strapped onto my head and leave my hands free. Yes, I do look like a geek, but it's very, very, useful.

Junk Box

If you do enough installations, you'll have one soon enough. Keep everything that you don't use and before you know it you'll have screws, brackets, knobs, wires, fuses, and other assorted stuff that will make your life easier.

Next, I like to look at all of the components that I am installing and figure out what each one requires. I usually start at the trunk and work my way forward. This means that I put the antenna in first and then the radios. No real reason for this, it's just the way that I like to work. Do what works best for you. While you are doing your inspection, try to figure out what you might need and make a trip to get it before you start so that you don't have to make an additional shopping trip, or more likely, several trips.

Sometimes you will run into something unexpected, but you should be able to figure out most of what you need beforehand. This also means that you should look through the installation directions and see what is not included in the box with the radio. Mobiles don't usually come with antennas, wires may not be long enough for your application, fasteners may not work with your desired location. Save yourself some aggravation and read up first.

Drilling
Perhaps the most nerve wracking part of installing radios is drilling that first hole in a new vehicle. You can avoid some of this anxiety by carefully measuring the location where you are going to drill. I sometimes measure three times to make sure that I am happy with the location. Know where the drill is going to end up.

On the trunk, make sure that when the drill comes through, it is going to come through in a location where you can get at the cable and the mount will fit. If you are drilling to install a radio or other component, make sure that the drill is not going to go through and cause damage to another part of the vehicle. Mark your hole first with the scratch awl, ice pick, or spring loaded punch. Any drill larger than about 1/4 inch will "walk" across the surface and make a huge scratch if you don't have either a pilot hole or a good indent marked on the spot.

Hole saws come with small pilot drills, but bigger drills don't and can cause some very ugly marks. When you have drilled through, there will be some small metal shavings left on the surface. Don't wipe them off with a cloth or towel. This will cause scratches in the paint and mar the surface. Gently blow the shavings off. You can wash them off when the work is finished.

If you are mounting the antenna on the roof of the vehicle, as you may have to do in pickup trucks and SUVs, there are a few things that you can do to make things easier. In pickup trucks, look to see if the headliner can be removed or dropped even a few inches. I've found that the most of the trim around the headliners of these vehicles can be easily removed and the headliner will drop.

This make antenna installation pretty easy. If you can't drop the headliner, you have a couple of options. First, you can remove the overhead interior (dome) light. This often gives you a spot to drill through and an opening to snake the antenna cable through. Look carefully at the inside of the roof to make sure that you have sufficient clearance.

In most cars and trucks the windshield pillar is hollow and the cable can be snaked through them. In pickups you also have the option of running the cable down the rear corners of the cab. If you can't remove the headliner, and for some reason the dome light location isn't feasible you are better off spending the money to buy an antenna hole saw.

Otherwise you run the big risk of drilling right through the headliner, and that isn't pretty. This is also a situation where a commercial snake is a better option than a coat hanger. It's longer length will be helpful in snaking the wires through to the radio.

If for some reason, you can't or don't want to install the antenna through the roof of your truck or SUV, you can opt to mount it on the front fender. Several manufacturers make brackets for mounting antennae on vehicle fenders. These are relatively easy to install and offer an alternative to roof mounting. Also, there are at least two companies that make mounts that fit in the "stake pockets" on pickup truck beds. Or, you can make your own mount as I did. Take a look at the picture and you will see what I mean.

Running the Wires
The most time consuming part of the job is probably running the wires through the vehicle interior. I have found that the easiest way to do this involves taking out the seats.

Another Warning: I have been told by someone else who does installations that they have been warned to be very careful when removing seats. Some vehicles have sensors for the air bags under the seats. Be very careful when disconnecting wires under seats.

Most antennae come with 12 or 15 feet of cable. For most cars, if you are running the cable from the trunk to the front of the vehicle, that is just not enough cable. I end up running the cables and wires under the carpet near the center of the car. This not only gives me plenty of room, but also gets the wires away from the automobile's wiring harness, which can avoid interference. I unbolt the front seats, or sometimes just the right front seat.

I also take out the back seat, so that I can run wires from the trunk into the interior. If you are only installing one radio, you can probably skip this step. But, if you are installing three or four antennae, a radio, and other components, you are going to want the space this provides. Front seats are generally held in by four bolts. The rear seats are held in by spring clips or are sometimes bolted in. It takes a few minutes to remove them, but believe me it's worth the effort.

After you have the seats out, gently lift the carpets. You might have to remove the scuff plates that are attached to the door sills. On many models, these also hold down the carpet edges. Usually, they are screwed in, sometimes they use snap clips. Remove them and lift the carpet edges. You will now have plenty of room to run wires under the carpet, out of harms way. I try to get them as close to the center as possible, to keep them out from under passenger's feet.

You may also have to run wires from the engine compartment through the firewall into the passenger compartment. If you plan on installing any sort of transmitter, you will want to run the power wires right to the battery. In a modern car, this can be a real chore.

I have found that there is usually more working room, that is more space to drill through the firewall if you have to, on the driver's side of most vehicles. Sometimes there are holes in the firewall that you can use without drilling. The passenger side of the car contains the hardware for the heater and air conditioning and takes up almost all of the available space on that side.

The problem with running the wires on the driver's side is that in many vehicles the battery is on the passenger side. This means longer wiring runs, which is more work. However, in the long run (no pun intended), it will be less work.

An alternative which works for simple installations is to run the wires along the fender and try to feed them in through the boot that covers the wiring from the door. This works well on larger Ford and Mercury vehicles, and probably some others. I wouldn't advise running more than 3 or 4 wires through this area, but if you are doing a simple install, it should work fine. Be very, very careful when you are opening the boot. I've found that an X-acto knife works well. Cut on the bottom of the harness, making a slit just large enough to pass the wire through.

I have found that for complex installations, it works out best when I run a heavy (12 gauge or larger) wire into the interior and install a separate fuse box just to run the after-market electronics. I also protect the circuit at the battery end with a 30 ampere automotive circuit breaker or fuse. Then I run individual power wires into the aftermarket fuse box and protect them with a fuse. In this case, I cut out the fuses that come with the radios and use straight runs of wire to the radios.

NOTE: Fuses should always be put as close to the power source as possible. This provides for maximum protection against short circuits and possible fires.

If you are doing a simple installation, that is, one or two scanners, you can try just tapping off of the vehicle's fuse box. Most vehicles have one or two spare slots in the fuse box. You can tap into these and run a scanner or two easily. The down side here is that you may end up picking up some ignition or alternator noise in the scanner audio.

A lot depends on the type and age of the vehicle, but most modern cars are pretty well filtered. Remember that you have to fuse the power wires of the scanner, since you will be picking up the power from the unprotected side of the fuse box. Also, some of these circuits are controlled by the ignition switch and will be dead when the key is turned off.

This can come in handy, but be aware of it. This is where your multi-meter or test light can help. Test the terminals to find the unprotected side of the circuit and test for whether it is ignition controlled or not.

Don't forget when assembling antenna cables to install all of the parts and in the correct order. Anyone that's done any number of installations will recall with some embarrassment the time that they put the connector on but forgot the outer shell or put it on backwards. Take your time with this step and you won't have a problem.

Installing the Radios
After the various wires are run, it's time to put in the radios. Given that modern cars are generally smaller, this can be a challenge. Also, the interiors of cars are now made mostly of plastic. This can make it tough to install radios since there isn't that much to bolt them to. Luckily the popularity of cellular phones has given us all sorts of options. If you have a car without a center console, your task is much easier. Cars with center consoles present an additional challenge, but it's not impossible to have a nice installation.

Big Warning Here: Almost all new cars have dual airbags. Whether you like them or not, you do have to take them into account. Do not, under any circumstances, for any reason, install any radio or accessory in the deployment path of the airbags. Serious injury or death will result. Airbags deploy at incredibly high speeds (200 MPH) and any objects in their path will become projectiles. The best way around this is to mount everything as low as possible and as close as possible to the dash UNDER the airbag path.

NOTE: If you are going to be working during cold weather, take some time to get the vehicle warm before you start to work. Plastic panels in particular can become brittle in cold weather. This makes breaking a part of the interior a lot more likely. A warm vehicle is much easier to work on.

Okay, back to the good stuff. As I noted above, the great popularity of cellular phones gives us all sorts of options. I recently picked up four pedestal style cellular mounts at a flea market.. These are designed for mounting handsets or portable phones, but work great for mobile scanners. Once you mount the radio and bracket on the pedestal, you can tilt and swivel the radio to get a good viewing angle. When possible, I like to mount this to the center hump of the vehicle. This keeps the radios low, out of the way, and yet handy enough for you to be able to reach the controls. With a little ingenuity, you can stack a couple of radios on one pedestal. Another nice thing is that you can, if you have to, mount the bracket on the side of the console and adjust it to get the radios where you want them. I like to mount the radios on the mount first, and then adjust the mount to find the best location on the console. Then I take everything apart and mount it permanently. This doesn't always work, but it's a pretty good place to start.

Here are a couple of hints on mounting things on the center hump of the vehicle. First, don't give into the temptation to drill through the carpet into the floor. Drill bits will often grab the carpet material and create a big run in the carpet. There are two methods that I have been shown to avoid this. I learned these from guys that do high volume radio installations and know a lot of short cuts.

First, you can take a scratch awl or ice pick and punch holes in the floor with a hammer. The down side to this is that with thick carpets, it can be a bit of a chore to find the hole afterward. It takes patience to wiggle the screw around until the tip finds the hole. The other way involves using a power drill and "drill point" self tapping sheet metal screws. These can be found at most hardware stores.

I generally use the #12 x 2 inch hex head version. Those carpets are thick and if you use a shorter screw, you'll find that you have screwed the mount into the carpet and not the sheet metal. Line the bracket up and put in the first screw. Then, making sure that you like the location, put in the remaining screws. Don't worry about drilling through the transmission of rear wheel drive vehicles.

I've done dozens of these over the years and never had it happen, nor have I heard of it happening. That's not to say that it can't, but most rear wheel drive vehicles have plenty of space between the floor and the transmission. If in doubt, look first. On front wheel drive vehicles, the exhaust is sometimes routed down this area, but again, it should be a couple of inches below the floor and not a problem.

If the exhaust is routed here, you can be pretty sure that fuel lines and electrical cables are not in the same area. However, it does pay to try to take a look underneath the vehicle before you start.

Other Mounting Options
Anyone that spends any time on Strong Signals probably has seem me post about mobile installations. You've also seen me mention two companies that I have dealt with and find to have quality products. One is Panavise Corporation, www.panavise.com, the other is Canyon River Cellular, www.canyonriver.com.

Panavise makes two products which I have found very helpful. The first is called the PortaGrip 2000 cellular phone holder. Designed to hold portable cellular phones, they can be mounted on either the dash or on a pedestal mount. The Model 702 has a nice flat bottom and can hold the RELM HS-200, Racing Electronics RE-2000A, and the Uniden BC-245XLT, among other radios. The other nice device is the Indash series of mounting brackets.

These are designed to be mounted to the dash of your vehicle, without having to cut or modify the dash. They are designed to hold the Portagrip mounts, but can be used to hold radios. Again, see the warning about air bags.

Canyon River Cellular carries Panavise products and will order products for you if they don't have them in stock. I've dealt with them via e-mail and have found them pleasant and efficient. There are other companies and vendors that make and sell brackets, and an Internet search should help you find many of them. Again, ham and electronics flea markets are a great source for finding this stuff.

Some trucks and SUVs have space above the rear view mirror to mount radios. There are even some after market consoles that install above the windshield that include radio mounting slots. This will require extra wiring, and maybe even a microphone extension cord if you are installing a ham or commercial radio, but it's an option worth considering. An Internet search of "overhead consoles" will give you several sources.

Installing a radio overhead may require making additional brackets and is not for the faint hearted. If you want an overhead installation, but don't want to make your own brackets, take a look at the aftermarket consoles available.

If you are installing a two way radio with a remote head, you might be able to install the head in an opening in the dash. Many foreign cars, and some American vehicles, have openings in the dash for add-on CD players and other accessories. They are usually too small to install a mobile scanner, but are pretty good for the small and light front panels that many modern radios, especially ham radios, have as options. Again, you may have to make your own brackets, but the results can be very worthwhile. This is an area where using Velcro can come in handy.

Many commercial and some amateur radios can be mounted remotely. The transceiver unit can be mounted under the seat, in the trunk, or even behind the seat in pick up trucks. When selecting the location, be very careful of what you are drilling or screwing into. Always determine what is behind the mounting location.

Many modern cars mount the gas tank up over the rear axle, right under part of the trunk of the car. Although the location looks tempting, I am always a little bit leery of mounting the radio there. If the radio is light enough, I like to mount the unit under the package shelf, which is under the rear window. There is usually enough room to drill holes and mount screws if you are careful.

To Sum Up
You will reap the biggest rewards if you take the time to plan ahead. Before you drill the first hole, think through every step of the process. Planning will reduce the chances of making a mistake, and probably will make any that you make smaller and easier to fix. Doing your own installation work can be a lot of fun. You will have the pride of knowing that you did the work yourself.

Gary Saffer
garys2@mediaone.net

Pictures From A Recent Installation