I'm hoping that someone can give me some advice on how I could change my auxillary 12 volt power point so that it would be keyed or powered only when the truck is running rather than being on all the time. Or even better how I might add an aftermarket power point under the dash somewhere and what I could hook it into so that it would only be powered when the truck is running.
The reason is my GPS unit will turn on and off on it's own providing the power supply to it is keyed on and off and adding a new socket / power point would also allow me to hide the wire and plug as well.

I,ve done lots of electrical work in my home, but never anything on a vehicle, and after looking under the dash the other day I figured I'd better get some advice, before I screwed something up under there.

I haven't had much luck searching for this and would appreciate the advice.

Thanks..........

 

Look through these photos & their captions. Yours is similar.

 

Thnaks Steve83, not sure I'm any less confused though, I did find something off a link to your pics regarding a fuse tap which looks like it would work.

So where's the best spot for a fuse tap to go for "ignition on" power? And do you just ground the other wire? and if so where? Thx!

 

Those questions sort of answer themselves:
A fuse tap for ignition power would go on a fuse that's on ignition power.
The ground wire goes to any good ground point - generally, anything metal that's permanently attached to the body or frame.

It sounds like you're not very experienced in electricity, but "ground" on a vehicle is just like "ground" on a building - it's a common return path for the current used in the circuit. On a vehicle, that path is the metal of the body, frame, & engine block to the 2 power sources: the battery & the alternator.

If that's still confusing, you should probably pay a pro to handle this. Even an "insignificant" circuit can be dangerous if it's not protected. Witness the recent cruise recall: