Vehicle mounting challenges

[lucasec]

DMR questions aside, I also need to figure out the installation the last few installation details. Would appreciate any input from the experts .

I originally measured and thought I could place the radio up behind the driver's side dash. While this looked good on paper, with the unit actually in hand it's very tight. Probably too tight. Might still be possible to get a single deck there, but only after taking a lot of other parts loose to make enough access to the space. And I'm definitely not stacking two decks without interfering with some positions of the steering column.



Under either seat is definitely ruled out too.

My present thinking is the best spot is probably on the side of the cargo area. Given the slope of the sidewall, placing it just below the trim piece for the cargo cover doesn't eat up too much cargo space since that piece already juts out. Could add a second deck to the side and maybe fashion some kind of shroud to cover the decks/wiring. Wiring would be a bit of a pain though.



Trunk floor/spare tire area is already filled with an OEM subwoofer.

Anyone see any other options I'm missing? I haven't taken apart the center console to see if there are any cavities in there, but that would be an enclosed space which I assume isn't great for ventilation.

 

[DeoVindice]

Is there any kind of compartment under the rear seats?

 

[lucasec]

Sadly no compartment under the seat. Found this video of someone taking all the the seats apart:

It's basically the seat cushions then sheet metal right below that.

Very little space wasted in my "subcompact" SUV it seems .

 

[DeoVindice]

That's unfortunate. I was able to use the under-seat jumper cable compartment on my pickup to mount the ROIP system, since I keep cables in the toolbox instead.

Under the seat is the usual recommendation for that kind of vehicle. If you can't make that work, the trunk side mount may be your best option. Wire loom will be your friend to keep things tidy.

 

[mmckenna]

If it was me, I'd get some nice finish grade plywood, probably 1/2" or 3/4". I'd cut it big enough to hold 2 RF decks with room for proper cable routing. I'd probably trim it to match that part of the plastic panel. I'd paint it black or dark grey. I'd use some long screws to go through the sheet metal, plastic trim, and into the sheet metal. I might do 1/4" threaded rod cut to the proper length instead of long sheet metal screws.

That would give you a solid mounting platform that wouldn't come loose in an accident (#1 concern) and would look decent. Use a hole saw to make a hole in the plywood and plastic trim to allow cable routing.

#6 cable from the battery + terminal to that, and install a fused distribution block to feed the individual radios. Pick up a local ground off the sheet metal.

You could fabricate a cover to protect the radios.

No way I'd mount under the dash, even one RF deck.

 

[tweiss3]

I would recommend mounting it on a sheet of plywood as mentioned above. You can spray paint it if you want, then side mount it it in the trunk easier.

 

[lucasec]

Plywood to use as a base to make mounting easier than having every component (RF deck, distribution block, cover) mount directly into the sheet metal? I need to pull that carpet up to see what's behind it, but I believe it's pretty much straight on sheet metal.

The little mounting bracket that came with the radio sets the radio about 3/4" off the base of the mount. I assume that should still be respected for airflow purposes.

On the plus side, I am most certainly glad that I got the 17ft cable for the HHCH. It has plenty of length to run from the cargo area to the front with still several feet to spare/cable manage.

(for any late joiners—this thread was split off of Best Portable/Mobile ecosystem: NX-5000 line vs Motorola R7 + XPR5000e, which mostly ended up with us discussing the Kenwood NX-5000. Vehicle is a Mazda CX-30 subcompact crossover.)

 

[lucasec]

Quick question for you folks... how do you usually mount these little microphone hook hangers?

The kit came with some sheet metal screws which I assume are intended to go directly into some plastic part of the dash. It seems like these would easily tear out of the soft plastic found on a lot of modern cars. Would you use the screws or go for an adhesive such as VHB?

 

[mmckenna]

Quick question for you folks... how do you usually mount these little microphone hook hangers?

The kit came with some sheet metal screws which I assume are intended to go directly into some plastic part of the dash. It seems like these would easily tear out of the soft plastic found on a lot of modern cars. Would you use the screws or go for an adhesive such as VHB?

The sheet metal screws are fine as long as you don't drill too big a hole. Just finished installing a bunch of radios in buses, and where the wanted the mic made it nearly impossible to do anything other than sheet metal screws without tearing the whole dash apart. The previous buses had the same thing and had been in use for 15 years without issue.

However, keep in mind that if you are using a commercial radio, the mic clip ~usually~ needs to be grounded for the hang up functions to work. Usually it's easier to put a machine screw with a washer/lock nut and use a crimp terminal to ground it.

If you wanted to go one step further, consider the MagnetMic products. I switched over to those years ago and really like them. Makes removing/replacing the mic easier and you don't have to take your eyes off the road.

Magnetic Mic - The Ultimate Magnetic Police Radio Mic Clip

Magnetic Mic is a universally-compatible mic clip for police and CB radios. It uses a super strong magnet to make hanging your mic faster, easier and safer. It's the microphone holder that lets first responders stay focused on what matters.

magneticmic.com

 

[lucasec]

However, keep in mind that if you are using a commercial radio, the mic clip ~usually~ needs to be grounded for the hang up functions to work.

Interesting, had no idea about this one. The mic is the Kenwood KCH-21RM, any idea if that one requires grounding?

The hook function seems to work with me just holding the bracket my hand at least (didn't know I was that good of a ground )

 

[AK9R]

In my limited experience with programming Kenwoods, the hook function is programmable. IOW, the radio can be programmed to require the mic to be hung up -OR- the radio can be programmed to not require the mic to be hung up.

One useful configuration of the hook program is to stop scanning and revert to a "home" channel when you take the mic off hook.

 

[lucasec]

In my limited experience with programming Kenwoods, the hook function is programmable. IOW, the radio can be programmed to require the mic to be hung up -OR- the radio can be programmed to not require the mic to be hung up.

One useful configuration of the hook program is to stop scanning and revert to a "home" channel when you take the mic off hook.

Yup, they have quite a few options ranging from no hook-dependent functionality to stopping scan or activating monitor mode on off-hook.

Only question is whether it relies on the hook hanger to be grounded to detect the hook state reliably. At least in my testing it seems not to, but could have been dumb luck.

 

[mmckenna]

Yup, they have quite a few options ranging from no hook-dependent functionality to stopping scan or activating monitor mode on off-hook.

Only question is whether it relies on the hook hanger to be grounded to detect the hook state reliably. At least in my testing it seems not to, but could have been dumb luck.

Forgot you were using Kenwood.

The Kenwood mic buttons have two insulated parts. There's the button part, and the back of the mic. When those are shorted together by the mic hook, it'll perform the programmed action. So the mic clip does not need to be grounded on these Kenwoods.
But, by habit, its wise to ground it while you've go the dash opened up. Saves time if you decide to swap radios later.
I've been doing this for a few decades now, and I always ground the mic clip just out of pure orneriness/habit.

 

[lucasec]

Thanks for all the info on the mic hook. I'm trying to track down some specialized plastic (thread forming) screws. Ok maybe excessive if the sheet metal ones do fine in your experience but those should make it extra resistant to abuse.

My dash has a very difficult shape to mount anything flat to, so I got creative and 3D printed a custom shim, which also means using some extra long screws. Feel free to tell me if the overall idea is stupid.



The top half of the dash is easier to remove than the bottom, so if the screws ever tear out or I put in a radio that needs a grounded hook, should be possible to switch the top screws to a nut/bolt and ground it from behind.

Anyway, once that's out of the way, my next noob question is where to attach my power wire to the battery. I got the 6awg wire and breaker as mmckenna recommended. I think I have a decent place to mount the breaker in the engine compartment (blue box in first photo).



Last challenge is my battery has this complicated harness off the positive terminal. It has some unused lug attach points that seem enticing, though the connections behind the clear plastic I assume have some sort of current rating on them I may not want to mess with.

 

[mmckenna]

Thanks for all the info on the mic hook. I'm trying to track down some specialized plastic (thread forming) screws. Ok maybe excessive if the sheet metal ones do fine in your experience but those should make it extra resistant to abuse.

I think appropriately sized sheet metal screws would be fine, but if you can source the thread forming screws, that should work. Unless you have a large primate utilizing the microphone, I doubt you'll have an issue.

My dash has a very difficult shape to mount anything flat to, so I got creative and 3D printed a custom shim, which also means using some extra long screws. Feel free to tell me if the overall idea is stupid.

No, that's impressive. I played with 3D printers for a bit, but never got too handy with it. That's a pretty cool idea.

The top half of the dash is easier to remove than the bottom, so if the screws ever tear out or I put in a radio that needs a grounded hook, should be possible to switch the top screws to a nut/bolt and ground it from behind.

Anyway, once that's out of the way, my next noob question is where to attach my power wire to the battery. I got the 6awg wire and breaker as mmckenna recommended. I think I have a decent place to mount the breaker in the engine compartment (blue box in first photo).

That should work just fine.

Last challenge is my battery has this complicated harness off the positive terminal. It has some unused lug attach points that seem enticing, though the connections behind the clear plastic I assume have some sort of current rating on them I may not want to mess with.

View attachment 181770

So, if it was me, I'd probably come off that threaded stud on top where it connects to the battery.
Issue with those fuse centers is that if you blow something, you have to replace the entire thing. I've never priced one out, but I'm betting they are not cheap, and not something you would likely be able to source at an auto parts store in the middle of nowhere.

In those little window are fuses. You pop one, you replace the entire module. A nice space savings idea, but a pain if you have a fault.

On the other hand, they are likely rated higher than what you need, so if you had the circuit breaker, you could feed off one of them. Would look pretty factory stock and hide well. Looks like there's ampere ratings marked on them, but I can't read it.

Chevy uses those, and so far I've not messed with them. I come off the positive post. Just easier if you have an issue and don't have a GM dealer nearby.