My first thought was: Antenna clipped to the edge of the truck bed – easy right! How am I going to get the antenna wire poked into the bed of the truck? There is nothing back there, no holes, no grommets. For a commercial vehicle this makes sense for the eventual tool-cab or dump body – pop off the bed – no wires to deal with. I followed the existing wire loom and it travels along the frame, under the cab, and up through the firewall. So, if I wanted an antenna mounted to the lip of the bed, I was going to need a 30′ coax detour. Not to mention exposing that wire to the elements and spending 3 hours on my back with zip ties.
Plus, I have a tonneau cover. The edge of the bed isn’t exposed, and I’m not drilling a brand new hole in it. Time to re-think this whole operation.
Fender mount! Why stretch wires all over the cab when I can grab power and antenna from the same area? I did a search for these online and the premise is a metal bracket that attaches to one of the fender (or hood latch) bolts on the front of the truck. There are many available, but not for every truck, and they are not usually inexpensive. I was considering ordering one that looked like I could modify it to fit, but for $66 + shipping, that’s an expensive experiment. Instead I made my own! If you own a vise, a hammer, and a drill – you can build this.
For $8, I grabbed a flat bar of 1/16″ (or 3/32″) 2″ wide steel from the local hardware depot. Hood up, cardboard template gave me an upside-down “2” shape. I marked up the steel and into the vice it went. Hammer, hammer, hammer, fold, check fit, hammer, check fit, repeat! Making sure that the hood had clearance and that the mount would press snugly against the fender. I was able to cut a slot for the hood bolt using a grinder. A dremel could do it, or a hand drill would work here. I sanded the edges and coated with Rustoleum Flat Black Trim Paint. For the Antenna itself I now had a platform for an off the shelf trunk lip mount. I chose a Tram 3246-B SO-239 mount as I re-used the antenna from my old truck (a Diamond NR770HB). It’s close to a factory look, as this is where the FM antenna would go on older trucks. Also I chose the drivers side specifically because the ECU (PCM / Computer) is bolted to the firewall on the passenger side. I want to minimize electromagnetic interference from this, and 65 watts of EMR (electromagnetic radiation) getting into this.
The grommet through the firewall is over-sized enough that I was able to squeeze the UHF connector through intact. The Power distribution bus on these new Chevy trucks are fantastic and I had fused ground and positive wires going right to the battery using ring terminals and existing bolts. Now power and antenna were in the cab. Where do I put the radio?
In the 2014+ Colorado, there is a nice storage shelf under the rear seats in the crew cab. If I was running multiple radios, or additional equipment, I think I would take the time to route everything back here. This would of course necessitate removal of the center console to route the wiring under the carpet. In our old Blazer I didn’t take the time to do this and occasionally dragged things over the “neatly zip-tied, but totally in the way” wires running along the floor. The center console is like a sealed piece of Tupperware that’s not quite square inside, and gouging giant holes in the bottom for wires and radios would render the storage area useless. I instead turned my attention to the front seat.
My Kenwood TM-V71A roughly fit in the area, but I was worried about the seat mechanism hitting it. I picked an area of the floor that I felt would be clear, and then moved the seat into “wife is driving” mode. The radio would be crushed by one of the seat motors. “Well, maybe the radio moves with the seat?” I situated the rig against the round bar in the middle of the seat and tried various positions – it seemed to work! I then went back to the vice and fabricated an aluminum bar with tabs to bolt onto one side of the rig. Using pipe clamps I got it into position and tried moving the seat. It actually pivots a LOT more than I expected, but I was able to find the angle where: At full depth it’s tucked up into the seat, at full height it’s lightly touching the floor. I then moved the seat all the way forward and all the way back to make sure I had clearance. It worked out great! Here’s VIDEO of the seat and radio going from all the way up – to all the way down.
A nice doughnut of spare coax was made à la choke coil and everything was zip-tied up and checked again for clearance. The remote head and speaker wires were run up the side of the center console. The mic connection on this mobile rig is now in a great spot, and because the radio travels with the seat there is always enough cord!
- Generic parts:
- $8 Flat bar of steel
- $4 Aluminum bar (scrap)
- $30 Trunk Mount (Tram 3246)
- $42 Subtotal
- Radio Specific Items:
- $50 Diamond NR770HB (I owned from previous install)
- $40 Kenwood DFK-3D Remote Mount Kit (previous install)
- $90 Subtotal
- $130 Total