I bought a car dock for my HTC EVO 3D (http://shop.igrip.us/igrip-perfektfi...3A209A9051.htm) and I would like to run power to it so that the micro USB cable comes up from the back of the dash. I would like it to deliver power when the car is on, but not when it is off.

I ran several searches, but couldn't find details on how to do this. Are there any how-to documents and/or threads available that can show me how to do that?

Thanks!

 

Be very careful doing this USB's are normally 5v. Cars are 12v if you wire those together and plug your phone in it could do some damage. (I only say this b/c there isn't alot of info on that website to go off of) let us know when u get it if its rated for 12v or what not.

If its 12v It'll be easy.

 

I've been doing a lot of reading and search today and I think I'm going to purchase one of these:


I will then cut off the mini-usb end and wire in a micro-usb end. Does anyone think there is anything wrong with this solution?

 

yeah watch yourself.

you know how ipods charge through a usb cable right, a usb cord has 4 wires, +,-, data+, and data-, well most usb chargers only supply the positive and the negative. Ipod touch/ iphone chargers have a series of resistors in the tip that go to the data +, and data- lines, cause the ipod needs to detect 2.5v and 2v on those 2 data lines before it will charge.

Best bet and how I did mine, buy a car charger that works for your phone, find a 12v source in your car, the cig lighter is good, tap those wires. twist a wire around the side spring things on the charger and put electrical tape over it, thats the negative, unscrew the nipple thing at the tip of the charger and stick a wire under there and screw the tip back on so it gets stuck, cover with tape.

any questions?

 

I have an HTC EVO 3D and I don't think it requires the data lines in order to charge. I will just wire the green and white wires together to complete that loop and not use them at all. I'll obviously test it before wiring it in to my car to make sure it charges the phone.

If the Nuvi hardwire cable doesn't end up working, then I can do something like what you mentioned. I'd rather use the Nuvi cable though just because it's a cleaner solution. Thank you for the advice!