Posted: 9/12/2011 7:46:02 AM EDT
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I'm expecting a bunch of stuff to show up in the mail today to do my mobile install. First was going to have a Motorola shop do it, but found out both local places wanted $100-$300 to run 12g power line, install an NMO, and mount my radio (Kenwood d710a). I've read the K0BG site & many others.
Going the DIY route with a Pro Fit GMC hood mount antenna & Larsen 2/70B. I can drill my own roof hole later if necessary. The firewall grommets in my '11 GMC 1500 crew cab pickup are crammed full and the battery is against the passenger side firewall. There is only room for the radio unit all the way in the back. What do you guys think about the following plan? 8g zip cord, connected to battery directly, fuse on both. Fire resistant wire loom & zip cord running from battery to passenger door grommet. the loom is protected from abrasion, impact, and heat. There looks like ample spots to zip tie the loom to the body. Entering through the door rubber grommet mostly out of sight, sealed with ultra black RTV. From there, a short bit of loom inside as it passes into the cabin. Power wires then run under passenger side door trim to main radio, to be mounted behind/under rear passenger seat if I can make a bracket. I'll run a Powerwerx voltage sensing switch in the line to kill power after the ignition is off. Driver side antenna mount, RTV to seal the NMO mount against the elements. Coax run like the power wire, but along the driver side. Kenwood's own proprietary shielded cable as a mic extension (plugs into main box), with RJ45 coupler between mic & cable. Plain Cat 6 cable for the control head. An MFJ cheap extension speaker somewhere up under the dashboard. I don't know whether to run the mic/speaker/control cables alongside the coax, power, or try to find another way. Of the two, which would cause less interference? Drilling an NMO into the roof would free up the driver side door channel for control cables, but wife unit is understandably not thrilled about the idea of me taking a power tool to our 6 month old Denali. That may be doable in a couple years. I also go into garages too low for the Larsen antenna. It would have to be my Comet SBB1 on the roof most of the time, maybe not even as good as the fender mount Larsen. Thanks in advance for ideas & comments. I'm still scratching my head over exact mounting spots for the box & controller. Space is cramped if I want a lo pro install. Posted Via AR15.Com Mobile |
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Everything you could ever want to know about mobile installation can be found at www.k0bg.com
ETA: missed that you already checked that site. 
As much as the wife objects, I really would go the NMO mount. I use a mag mount, and it's hit and miss. All said, I'd probalby drill next time. |
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I'm very close to doing the roof NMO. The Pro Fit mount is an NMO that fastens to one of the hood hinge bolts, so is still fairly permanent.
I have a Diamond clamp mount, but find that it leaves marks on the paint such that a permanent bracket or 3/4" hole would be better. Posted Via AR15.Com Mobile |
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My only advice is this,
I would not use 8ga zip cord, 10ga max. For wire larger is always better, especially for long runs, but with the increased diameter you have more of a chance of chafing and pinching. The difference between 10ga and 8ga is significant. It is a 50 watt mobile and smaller wire would be sufficient, but 10 gauge will give you wiggle room, 8ga is overkill. I went into the door grommet on my car and it works fine, zip ties work well. I suggest the expandable type wire loom zip tied into place, the stuff GM likes to use on the factory wiring harness. That stuff is tough as nails and adds some abrasion resistance. |
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Quoted: I'm expecting a bunch of stuff to show up in the mail today to do my mobile install. First was going to have a Motorola shop do it, but found out both local places wanted $100-$300 to run 12g power line, install an NMO, and mount my radio (Kenwood d710a). I've read the K0BG site & many others. Going the DIY route with a Pro Fit GMC hood mount antenna & Larsen 2/70B. I can drill my own roof hole later if necessary. The firewall grommets in my '11 GMC 1500 crew cab pickup are crammed full and the battery is against the passenger side firewall. There is only room for the radio unit all the way in the back. What do you guys think about the following plan? 8g zip cord, connected to battery directly, fuse on both. Fire resistant wire loom & zip cord running from battery to passenger door grommet. the loom is protected from abrasion, impact, and heat. There looks like ample spots to zip tie the loom to the body. Entering through the door rubber grommet mostly out of sight, sealed with ultra black RTV. From there, a short bit of loom inside as it passes into the cabin. Power wires then run under passenger side door trim to main radio, to be mounted behind/under rear passenger seat if I can make a bracket. I'll run a Powerwerx voltage sensing switch in the line to kill power after the ignition is off. Driver side antenna mount, RTV to seal the NMO mount against the elements. Coax run like the power wire, but along the driver side. Kenwood's own proprietary shielded cable as a mic extension (plugs into main box), with RJ45 coupler between mic & cable. Plain Cat 6 cable for the control head. An MFJ cheap extension speaker somewhere up under the dashboard. I don't know whether to run the mic/speaker/control cables alongside the coax, power, or try to find another way. Of the two, which would cause less interference? Drilling an NMO into the roof would free up the driver side door channel for control cables, but wife unit is understandably not thrilled about the idea of me taking a power tool to our 6 month old Denali. That may be doable in a couple years. I also go into garages too low for the Larsen antenna. It would have to be my Comet SBB1 on the roof most of the time, maybe not even as good as the fender mount Larsen. Thanks in advance for ideas & comments. I'm still scratching my head over exact mounting spots for the box & controller. Space is cramped if I want a lo pro install. Posted Via AR15.Com Mobile I'm skeered to poke holes in my Denali too.....and it's a 2007 model.  |
| It sounds like a good install. The only thing I would change is the location of the speaker. I tried mine where you're thinking. It didn't work out too well. Road noise, noise from an open window all seemed to drown it out. I finally went to a truck stop and got one that clips to my visor. It puts the speaker just above and in front of me. All the sound is directed right at me. It works great. I had to "stretch" the original speaker wire to reach from under my seat and around the dorr frame to the reach the visor. It wasn't a big deal. All of the wire is hidden behind trim panels except for the 3 - 4" from the trim aroun the windo to the visor. Just something to think about. |
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Quoted:
If you are going to mount the radio in the rear, why not run the power wires along the vehicle frame and bring it inside the cabin in the rear somewhere? This would eliminate all the "snaking" in and out of trim and grommets. I considered that using large durable welding cable. Turns out I got 10 zip, not 8g, so will just go inside. Posted Via AR15.Com Mobile |
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Updates. Progress was slow - my perimeter security team consisting of a boxer puppy and a an impatient 1 year-old were more of a time drain than expected. Not much later, the helpful 4 year old arrived to take the tools out and climb inside the car to "help" me by watching. It was charming, but didn't speed things up any. I cobbled together a support bracket for the radio's adjustable mounting bracket. Using a hole in the seat frame and a large bolt, there was no drilling through the body.
The antenna bracket is mounted with a Larsen NMO mount. The sticky black RTV is hateful for stickiness, and I slathered it all over the underside of the antenna mount & coax. The coax wires are run through the trim to the rear. The speaker extension wires run in the driver side channel, too. For now, the ext speaker is just zip tied to the structure under the dash to test its location. All the trim is back on then driver side. Pax side, the data & mic cables are run. I left a bit of nylon weedeater line alongside them under the carpet to drag through the 10g power lines tomorrow. Fused connectors to both battery terminals are installed, with 45A PowerPoles at the end. Tomorrow's tasks: run power line, install power poles, find mounting spots for controller and mic, install antenna. Hopefully power it up. Good night |
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I don't think it's been touched on yet, but you can save yourself some cost in copper and in firewall-hole-real-estate by not running both pos/neg 8ga through the firewall. Just run positive, and ground negative from the device right to the nearest clean spot on your chassis/frame.
I recently did quite a bit of wiring in my vehicle to include 8ga lead off the battery positive terminal, 80amp maxi fuse/fuse holder, 75a powerpoles, 8ga run to back of vehicle, into a blue sea systems fuse block. grounded the neg side to a nearby bolt into the frame. from there it's 12ga wire to a powerpole 4 way block in my center console, 2x 14ga powerpole leads to a powerpole outlet in the center storage box, and another 12ga lead out to my ham radio. also straight off of the fuse block are two 14ga leads going to 12v cig outlets one in the front of the vehicle, another in the back. I heart powerpoles. |
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Quoted:
I don't think it's been touched on yet, but you can save yourself some cost in copper and in firewall-hole-real-estate by not running both pos/neg 8ga through the firewall. Just run positive, and ground negative from the device right to the nearest clean spot on your chassis/frame. Typically not recommended with radios...but in theory, should work fine. |
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Quoted:
Quoted:
I don't think it's been touched on yet, but you can save yourself some cost in copper and in firewall-hole-real-estate by not running both pos/neg 8ga through the firewall. Just run positive, and ground negative from the device right to the nearest clean spot on your chassis/frame. Typically not recommended with radios...but in theory, should work fine. Hmm, wasn't aware of that. So far I can't say I've noticed any ill effects (running an FMT-350AR on that setup.) If it helps, the radio itself is also fused on both pos/neg and hell, nothing has caught fire yet =) I was originally concerned about possible noise from the vehicle's electrical system and was ready to slap a filter inline, but so far I've been lucky. |
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I've always heard folks recommend running straight from the battery. Per K0BG:
"I personally have never experienced a problem wiring directly to the battery as most factory wiring guides suggest. Nonetheless, Tom Rauch, W8JI, has an alternative scenario about not wiring directly to the battery, which he explains here. He does present a valid point. However, if you're running high power (>200 watts out) there are several very good reasons to follow the factory wiring guides, and wire directly to the battery or to the Jump Points (see last paragraph in this section). Main vehicle SLI (Starting, Lights, Ignition) batteries have four connections; two for the positive, and two for the negative. The smaller of these wires carry the accessory load, whatever that may be. The positive lead ultimately connects to the alternator, and the ground lead to a chassis point near the battery. Their size varies, but they're typically size #6 or #8. The larger wires, typically sized #2 or #4, are wired to the starter solenoid, and to the engine block. The positive lead only carries current during starting. The negative lead will always have some current flowing through it, as it is the negative return for the alternator. If you connect your radio equipment to the chassis ground point as Tom suggests, whatever extra current draw there is, flows across the accessory ground wire, and to a lessor degree through the starter ground. In most cases, there will be no noticeable effects. It should be mentioned that the negative power lead of all modern amateur transceivers, is also connected to the chassis of the radio; the basis of Tom's argument. If the transceiver's chassis is grounded at any point (purposely, or inadvertently), a small amount current will find it way back to the battery through the vehicle's superstructure, with little or no effect. However, if you're running high power (peak currents as high as 90 amps), the current flow across the accessory ground could become excessive, and might even cause it to fail. And like modern transceivers, the chassis of most amplifiers is connected to the negative lead, so here too, some amount of return current will find it way back to the battery through the vehicle's superstructure. If this current becomes excessive due to voltage drop across the battery's accessory ground, it can cause a ground loop to occur, creating havoc with on-board electronics. Yet another reason to properly size wire to minimize voltage drop (see below)." |