There are two places of switched 12 volts that I know of. If your T has the AC power inverter in the rear the thin wire of the 3 wire harness is 12 volt switched. If you pull your radio you can grab the ignition switch harness by reaching from the radio opening toward behind the actual switch. There you should be able to reach the ignition harness and test for 12v switched. I forget the wire color. Hope this helps.

 

Just run it off your fusebox using a fusetap...more reliable and safer than splicing, and its very easy to get power to anywhere in the dash area. Fuseboxes are on both sides of the dashboard, so pick whichever one suits your needs.

 

Hi Nickm,

what is a fusetap?

bagger

 

Fusetap allows you to tap into an existing fuse slot in the fusebox so that you can run a secondary power line with a of its own. Any auto parts store should carry them.

 

Not a good idea to 'tap into' other power sources without knowing the capacity of the wiring, fuse etc. Best way is to run a power wire directly from your battery (fused or relay - of course) to wherever you want it. Modern vehicles often have very sophisticated and complicated electronics (not like the 'old days') any interference with can cause havoc.

 

The size of the fuse should tell you the capacity of the wiring.

 

A fusetap allows you to safely add a power slot by having a fused power supply. There is no difference between running a fusetap and wiring it directly to the fusebox under its own fuse...

This is much safer than tapping into the lighter, as it is a fuse protected circuit.

Only reason to go direct to the battery is if you need high amperage ie: starter, amplifier, etc.

 

Just curious how everyone who has installed sat has hooked up their power source.
I installed mine this weekend, with the expection of finding a power source that works of the ignition.
I am currently using the 12v cig lighter as the power until i think of a place where i can tie into the ignition/radio to get a clean install.

any ideas?
vern

Did a recent project to add an Orange Tire Pressure Monitoring System to my 06 Touareg V8 and I found pretty much no place to pick up 12V switched under the dash, using a fuse tap on one of the 12V switched fused circuits is a good way. Be advised, most of the fuses are off of 12V un-switched 12V distribution feeds.

The only easy access to 12V switched under the dash is the diagnostic connector, it has 12V switched and ground on it, I don't recommend taking but an amp or so from here but that might be good to drive a 12Von/off sense port on your device if that is all you need. The 2 battery leads on the radio/nav head unit connector are both 12V un-switched.

Your final choice might be to do some interior disassembly and get to the wiring leading to the 12V accessory outlet in the center by the shift lever or in the back of the center console. Those are on 12V switched.

 

I'm not trying to get into a pissing contest here, but it only takes 150 ma to drive the coils in a Bosch relay. If there are two relays being driven on this circuit there should at most be a 1 amp fuse. Running 5 times that much (5a) is dangerous for the equipment currently connected and I am doubting that these are the only 2 items on that circuit although I say so w/o viewing the schematics. If there were any changes with a fuse panel, than current draw would probably top on the list. I highly doubt they VW would risk electronic equipment to save money on an ATM fuse. Sorry if I'm coming off harsh. I do not mean to be. I just believe there is something missing here as a fuse is one of the most important components in electronic safety.
At any rate if anyone is trying to locate a switched source to run any aftermarket equipment, then you can locate a switched source such as keysense wire at the ign. harness and wire a relay to amplify current. If you are fluent with a digital multimeter (no test lights) and have a relay I would be glad to assist.

 

There are no fuses in the Touareg fuse boxes smaller than 5 Amp. Each fuse is sized according to the wire gauge on the load size of the fuse. The size of the fuse and the wires on the load side handle the worst case load plus a engineering margin. For a 5A fused circuit, the intent is that under the full 5A load the copper wire does not increase in temperature more than a few degrees to avoid insulation failure or in the worst case an electrical insulation fire. For 5A circuit the wire gauge must be 22 or larger. The question at hand is how much load do the existing items on the circuit draw and can the circuit handle a little more load without overloading the fuse. The fuse can be larger than the load as long as it is small enough to protect the wire between the fuse and the load.

 

Good to know, then I guess we both agree that it is ok for the author of this thread to pull another 1.5 amps for a satellite radio because if this circuit is wired for the capability to pull five amps there would have to be a voltage supply of 2 volts or so, which wont happen or the resistance would have to increase 5 fold.
At any rate if cantex wants to play it safe, then just use this circuit or the keysense wire to drive a relay or just take it to a seasoned 12V installer.