Cobra 75 WX/Firestik II Install
By: Bob_98SR5
Last Updated: 3/30/03

Cobra 75WX CB Radio
4’ Firestick II Antenna
Firestik Adjustable Stainless Steel Channel Mount Mini Kit (MK-274-R)
Buss 6-gang Auxiliary Fuse Box
Rubber Grommet
1” Self-tapping Aluminum Phillips head screws
14-16 Gauge Plug/Ring Connectors
14-16 Gauge Positive and Negative Wire
12 Gauge Positive Wire
12 Gauge Ring Connector (2)

Choose between:
Firestik Heavy Duty Stainless Steel Spring (SS3-H)
Firestik External Quick Disconnect (R1-A)

Tools and Supplies
Power drill and drill bits
Tapping Oil
Philips Head Screwdriver
Ratchet Wrench
Soldering Iron w/ Solder
Crimping Tool
Electrical Tape

Obligatory Disclaimer
I am providing this write up for illustrative purposes only. Perform at your own risk. Any mods (including this one) you perform on your vehicle is your responsibility. Furthermore, commercial use of this write up is prohibited---all images and text are property of Linking or copying any portion of this write up may result in legal action.

Addendum (11/16/03)
I've re-mounted this original hood channel mount to the rear of my 4Runner in the rear cargo hatch area. Please click here and see if this hear mount is better for you.

On the trails, a CB radio is indispensable for communicating with your off-road friends. On the road, a CB radio can be just as valuable for communicating with other drivers and truckers by exchanging information on road conditions, exchanging alternate route information, reporting the location of highway enforcement, etc. One of my friends who makes cross-country trips as a big rig driver says that just by talking with other drivers keeps him fresh and alert. A definite plus for all drivers.

Of note, thanks to Mertzr (Tom) for his help and advice on installing my CB. His knowledge was invaluable to my write up.

Step 1: Mounting the Connector Box

Select an accessible location for this connector box. Doing so will allow you to easily plug/unplug the CB unit. Also when you have your CB tuned, choosing an easily accessible location will allow the tuner to easily tune your unit. My tuner advised me that he would charge more if he had to remove panels, wires, etc. Thus, I also chose to mount my CB where mertzr (Tom) mounted his:

View from the driver's side, in front of the shifter   The connector box mounted

On the driver’s side, I put the Connector Box up against the black frame (shown above) that supports the center console. With a pencil, mark two holes for the mounting screws. Drill two pilot holes and then using the supplied self-tapping metal screws, screw in the Connector Box to the black frame.

Of note, I inadvertantly pulled out the panel plug (see the big hole)? If you do the same, the part number to replace this little plug is 90467-07041-E0.

Step 2: Drilling a Firewall Hole
You’ll have to consider how you will run your coax as well as the positive/negative wires from the Connector Box. You may choose to try to poke a big hole and run the coax and positive/negative wires through the existing firewall grommet (located on the passenger side footwell) or drill a new firewall hole. I chose to drill a new firewall hole because I added an auxiliary fuse box inside the engine compartment for future accessory wires.

To make it easy to drill this new firewall hole, remove the driver's side panel (A), the doorsill trim plate (C) and the driver’s side footwell trim panel (B). Set all pieces aside.

Unbolt the four 10mm bolts to release the panel   Unscrew four screws on trim panel (C); pull out trim panel (B)

Unsnap the firewall padding clip and then fold and tuck it underneath to expose the bare firewall. You will also need to unplug the clutch connector (if you have a 5-speed). Next, drill a pilot hole and use progressively larger bits to drill a ½” hole. You may need to use an extension. Debur the hole and then insert a ½” rubber grommet.

Unclip and fold the carpet back to expose the firewall. Drill your new firewall hole here...   This is approximately where the hole will come out.

Step 3: Mounting the Hood Mounted Antenna Bracket
The gap between your quarter panel and hood may vary a bit from front to back. Thus, dry fit your mount and securely mount with the 5 self-tapping screws accordingly.

Mount somewhere along this area   Here's 3 of the 5 self-tapping metal screws mounted

There are a total of 5 holes in the mount. Mark the screw holes and then drill the pilot holes. You can then fasten the bracket down with the supplied self-tapping metal screws. When closing the hood, if the fit is tight, try using felt stick-on pads or tape the bracket itself. Mine is rubbing so I will have to put some felt on later.

Step 4: Preparing the Coax Connection
The Channel Mount Mini Kit includes 18’ of coax cable and the hardware to complete this task. WARNING: Whatever you do, do NOT cut the coax cable even if you need only half of it! This is the optimum length for the coax for CB operations. Don’t ask me why---the experts say so and I’m not arguing with them.

Take your coax cable from the outside and run the unthreaded end through your new firewall hole. Go inside and carefully pull the coax through, leaving about 1 to 2 feet inside the engine compartment.

Next, take your threaded barrel connector, slide it on the coax, and then push the coax onto the barrel connector. Slowly twist it in so the tip of the coax is at least even with the tip of the connector. Use some solder to secure the connection. After the solder has dried, screw the connector into the back of the power box.

Take threaded barrel connector (A), push and thread. Then take barrel connector (B) and slide over top   There will be a space around the wire coming out of the coax and the tip of the barrel connector (A). Add some solder into this space/gap for a good connection

Step 5: Attaching the Coax to the Antenna Mount and the Connector Box
Screw the coax and hardware onto the antenna mount with the supplied parts from the Mini-kit. See the picture below.

You will also have quite a bit of coax on the other end in the passenger compartment. I chose to run the coax under the driver’s side doorsill trim plate under the driver’s seat (12” skein-like coil), under the center console (towards the radio) and connect to the Connector box:

From top to bottom: Double-ended antenna nut, lock washer, plastic spacer, antenna mount, coax, and large nut.   Run the coax under the door sill trim plate, wrap excess coax under the seat in a "skein-like bundle", and then run the remainder under and towards the connector box under the center console.

Connect the end of the coax to the Connector Box.

Step 6: Making the Power Connection

I chose to connect my Cobra CB to an auxiliary fuse box. Make sure you unscrew and unplug both the positive and negative connection to the battery before going forward.

The ring connector shown will attach to your (+) battery terminal. This is protected by a 30 Amp in-line fuse. Use a butt connector and crimp a 10 or 12 gauge power wire. Protect with electrical tape or heat shrink tubing.

First, crimp on a ring-type connector to the end of your 30 amp in-line fuse connector. On the other end, use a butt connector and crimp on a 10 or 12 gauge positive power wire. On the other end of this positive wire, crimp on a ring-type connector. You will attach this onto your auxiliary fuse box.

Here's the Buss auxiliary fuse box mounted inside the engine compartment firewall. Notice the 12 gauge power wire running from the battery and to the auxiliary fuse box

After installing the auxiliary fuse box, go back to the connector box and pull apart the positive/negative wires apart from each other and run the positive through your new firewall hole. Crimp on a 14-16 gauge plug-type connector to the (+) wire and then plug it into one of the blades on the auxiliary fuse box. Put in a 15 amp fuse too.

Crimp on a 14-16 gauge ring connector to the (-) wire and ground it to a bare metal section on the firewall. I chose to mount the negative wire near the footwell trim panel.

Step 7: Mounting the Antenna and SWR Tuning

At this point, the install is almost complete. Screw on the spring mount onto the end of the Firestik and then screw it onto the antenna mount. Tune the antenna by testing the SWR. If you are inclined to do so and have the right tuning equipment, by all means, do it. However, if you’re a newbie like me and want a pro to do it, look up “CB” or “Scanner” on your local internet pages and find an expert. My tune cost $15 though I’ve heard cheaper prices from other members. My test took only 10 minutes and got a 1.5 reading on Channels 1, 19, and 40.

As for storing your Firestik when not in use, Mertzr (Tom) stores his here:

Clip on the headrest clips and drop your Firestik right in

Learning Points
Firestik has some excellent articles on…well, just about everything and anything you want to know about the CB world. I would highly recommend you read ALL their articles here.

Questions or feedback? Email me and I'll try to get back to you. If this article helped you save time, money or just made things more convenient for you, please consider donating to keep this site alive.