Before I start this post I want to acknowledge I found most of this information on the Model A board on the Ford Barn site and the HAMB. I recently made a 1600 mile round trip in my stock '49 Ford F-2 3/4 ton pickup. For added convenience and safety I wanted to use my GPS system and charge my cell phone but I thought I had to add some kind of 12 volt converter. I started to research the subject on the above boards and found that the new electronic devices run off of 5 volts, they use a smart charger and as long as they can sense a voltage source as low as 6-7 they'll send out the needed 5 volts to charge the device. Here's my contribution to the subject. I started with a dual port power port I found at my local farm supply store. I liked this unit for a few reasons. First it's made of metal, I've had problems in the past with plastic ones that the mounting ears broke off after inserting and pulling out the plug. Second, it had two ports, one for my GPS and one for my cell phone. I could have both plugged in at the same time. Third, I thought it looked kind of period correct and it tucked under the dash it wasn't as noticeable as the larger, clunkier plastic ones I found. Here's what I started with: Custom Accessories dual cigarette lighter receptacle part#49997 Custom Accessories - DUAL CIGARETTE LIGHTER RECEPTACLES Two 1/4" round head nylon round headed bolts Two 1/4" Keps nuts, eliminates the need for a lock washer One crimp on ring terminal with a 1/4" One crimp on ring terminal with a #10 hole One plastic insulator, I just cut a piece of 1/8" thick piece of plastic to fit Solder iron and solder Heat shrink tube If your truck/car is like mine and has the stock positive ground system you will have to maintain a negative ground in the power receptacle. You will have to insulate the case of the power receptacle from the metal of the dashboard. I cut the red wire coming from the center post of the receptacle, keeping the fuse holder for later use, attached the 1/4" crimp ring terminal. I soldered the fuse terminal to the black wire coming from the receptacle and covered it with a piece of heat shrink tubing. On the other end of the fuse I crimped on smaller #10 ring terminal to attach to the accessory post on the ignition switch. I cut the piece of plastic to fit and inserted it between the receptacle and the bottom of the dashboard, using the 1/4" nylon bolts and Keps nuts to fasten it to the underside of the dashboard. I also inserted the 1/4" ring terminal between one of the Keps nuts and the metal dashboard. I used this set up on my 1600 mile trip without a problem. Both my GPS and cell phone worked great. Whenever my cell phone got low I'd plug it into the receptacle and it would charge to full. I didn't notice if it took longer to charge in my F-2 than it did in my daily driver but I doubt if it did it was much longer.
Does the GPS have an AC charger that is used to charge a battery in the GPS? If so it might just be a type A USB or one of the micro USB jacks. The cell phones are suppose to be standardized to a micro USB jack. What I am getting at is that they sell cigarette lighter plugs which have USB and cord for accessories. Another approach is to build a simple boost regulator that inverts the polarity of the system and applies the correct polarity to the USB jacks.
I ended up buying a used Garmin 340 off epay. It has an 8 hour battery life and is perfect for those long drives in a 6 volt powered truck (on average, I put 3 or 400 miles on every weekend). ...Like you I had thought about hooking the GPS straight into the 6 volt system to see if the slight over voltage and generator would be tolerated. Now that I know that you've had success running on 6 volts, I think I will give it a try. Thanks for the tech from a died in the wool 6 volt car guy, -moe .
Good information,,I really never gave any thought to GPS with a 6 volt system but it good to know if I happen up on a car or truck which haven't been changed over to 12 volt. HRP
Slick solution. But the only caution I would have; is the body of the receptacle(s) is turned into "negative." So one would have to be careful of accidentally touching the rim(s) of the plugs with something of the opposite polarity. (e.g. - keys)
Great post. Thank you. I have a couple of clarifying questions. 1. So does the center post go to ign switch or to ground in a 6 volt post ground system. 2. Is this system based on using a 12 volt charger for a phone or a usb plug based charger or both. I ask because I thought they were diff. I think the usb chargers regulate voltage at 5 volts. So I would like to think this works w a usher charger going from 6 to 5 volts.....but wanted to ask because I have burned up two 12 volt non smart phone ( not a usb charger) chargers already. Thanks for any assistance. My kids need their ipods charged constantly it seems and I currently struggle w this. Thx mike
Great post. Thank you. I have a couple of clarifying questions. 1. So does the center post go to ign switch or to ground in a 6 volt post ground system. 2. Is this system based on using a 12 volt charger for a phone or a usb plug based charger or both. I ask because I thought they were diff. I think the usb chargers regulate voltage at 5 volts. So I would like to think this works w a usb charger going from 6 to 5 volts.....but wanted to ask because I have burned up two 12 volt non smart phone ( not a usb charger) chargers already. Thanks for any assistance. My kids need their ipods charged constantly it seems and I currently struggle w this. Thx mike
OK, bringing this back to the top to see if there is anything further to add by anyone, especially real experience (positive or negative ) using a 12V cigarette lighter USB output plug in a 6V positive ground car? I guess these chargers use an electronic regulator to get the 5V USB output, so will the 6V - 7V supply be sufficient to actuate the regulator? Wiring the socket isn't a problem, but explaining to my Boss how I destroyed yet another smart phone would be if this doesn't work!
I've been running both my cell phone and GPS using this set up for close to a year without blowing anything out. Seems to charge them both just fine.
Thanks Bob, so you just wired in the lighter socket, ensuring the outside can't short to the ground, and plugged in the 'phone charger?
Insulated the power port from the metal dashboard with the piece of plastic and used the nylon bolts. Just plug in the charger like you would in a modern car. You could short out the power port case if you ran a metallic object between it and the dashboard but you'd have to work on doing it. Not a problem in the time I've been using it.
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