Modern car stereos enable most of this, and various accessories do the rest. But I am a neat freak about car interiors. I hate wires running around the cockpit, giant plasticky mounts on suction cups, things that can get lost, things that look out of place, and so on. When necessary, I've been charging the phone with a cigarette lighter to USB adapter and a cable. Seeing all that sticking out of my 12V port drives me into a murderous rage, and there's nowhere in the cabin to put the phone where I can briefly and safely glance at it. So I decided to put together an in-dash USB power cable and phone mount.
- Major components -
- JVC KD-R810 stereo, Volvo wiring harness adapter, Metra single-DIN installation kit, or any other head unit that performs the same functions
Key features are: Bluetooth, rear USB port, single-DIN. I wanted rear USB because I really did not want a USB drive sticking out of the faceplate. A single-DIN unit lets me use the pocket underneath to hide things.
I bought this in 2011, and it's no longer produced. I can't seem to link to it, but Crutchfield's website lets you sort head units by features, and there are several that tick the boxes I've listed. The particular model is not important.
- Cheap USB car charger
This came from Walgreens, where I paid ~$5 for it many moons ago. It's chintzy lowest-bidder garbage, but it charges the phone just fine. The blue LED on this is useful for troubleshooting, and it should be sorta hidden in the final installation.
- Gooseneck flex arm with a 1/4-20 screw mount
Another victim of my sick obsession with hiding things is the phone mount. I cannot abide suction cup mounts, vent mounts, cig lighter mounts, cupholder mounts, and all the other easily-detached tributes to injection molding. I wanted something whose connection to the car would be hidden, and something I could mount near where my charging cord would come out, to minimize exposed cord length. I went with this stiff gooseneck arm, which has a 1/4-20 screw like a tripod, and one of the many adapters for cell phones, listed below. The clamp is not used.
- Cell phone tripod mount
With cell phone cameras being good enough for most uses these days, there are many mounts, of all degrees of complexity and cost, to attach cell phones to tripods. This one can be operated one-handed and is aesthetically inoffensive even with no phone mounted. It hangs onto the phone even through bumpity-bump in-town driving, but it is not a high-quality product. I don't know how it will hold up long-term, but it's replaced easily enough. The baby tripod with which this comes is junk; it should be discarded with great vigor, and perhaps pleasure. Don't hold back.
As the most important point of interaction with this setup is this mount, maybe I shouldn't have cheaped out on it. There were some other mounts that were quite pretty - "Reticam" and "i.Trek Super Mount" appealed - but the latter wouldn't work with my phone, and the former was too expensive to justify for something I was just throwing together. Since all of them use a 1/4-20 screw, maybe I can upgrade the mount later.
Other components, tools, and supplies include:
- a soldering iron, solder, and electrical tape
- some wire that you might solder to a PCB - I used some scrap wire from an S-video cable
- wire stripper
- zip ties
- rotary cutting tool (Dremel or similar)
- a short USB cable, so you don't have to deal with a giant, clumsy loop of a longer cable
- (optional) heat shrink tubing, zip ties, wiring loom, and anything else you'd like to use to beautify your cables
- Construction -
I'm assuming you already have an aftermarket radio installed, or ready to install. If not, I won't go into the details here, as there are plenty of guides out there. I highly recommend replacing your Volvo deck with something modern if you haven't already - the advantages I mentioned earlier are super convenient.
The basic idea behind the USB charging cable is to tap into ignition-switched 12V from the radio wiring harness and hook it up to a circuit that someone already made for you, from which you can charge your phone. Take apart the USB car adapter and you'll find a small circuit board that's hooked up to the leads from the cigarette lighter plug. The spring-loaded "ribs" are the ground terminals, and the spring-loaded "button" is +12V. The board doesn't care how it gets 12V, so we're going to power it from the radio harness instead of the cigarette lighter.
- Circuit board from inside USB car charger. Green is +12V, black is ground.
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- Board power hooked up to radio wiring harness
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- Wiring harness, loomed up with Techflex. Note the branch on the top right, which now goes to a powered USB port.
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- I did a very good job cutting within the lines. The radio rear USB port and the new USB charge port will go through this hole.
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- This is basically how it's supposed to work in the car.
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- Get the position and angle correct before you start cutting. You can adjust it later, but it may mean cutting or drilling more holes.
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- not so clean....I wish I'd had a drill for this, so I could drill holes for the zip ties instead of cutting them. I did melt some holes with a grinding stone, but it's not really a nice way to do it.
- All zipped in. Get 'em tight - you don't want this thing rattling. I did add one more at the end of the gooseneck after taking this photo, which made it more resistant to rotation and made adjusting the phone's position easier.
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- All done! Note that I plugged a 6" micro-USB cable into the USB charge port, so it's not too long and the blue LED is deep within the pocket.
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Obviously the exact setup I've described here isn't the only way to do this, but the total cost (excluding the radio and tools) was probably on the order of $25. Since I'm going to do at least 24-30 hours of road-tripping in the next few weeks, it's worth that just to have the phone secured and juiced up. The only problem I've encountered is reflections off the screen on a sunny day, but that is going to be true of any mount placed down low. It's way better than having to find and pick up the phone, and I'd rather die in a fiery crash than have to look at that charger plugged into my 12V port, so I'm happy with the results.
