Prepping for Colorado

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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.