S4 - 2004 Electrical Question

On Thu, 09 Sep 2004 21:21:58 -0400, Doug Warner >
wrote:

>"Keith Viator" > wrote:
>
>>I just bought a 2004 S4 and just installed my radar detector. I have always
>>"hard-wired" the thing in prior cars since I don't like the dangling power
>>cord going to the cig-lighter.
>>
>>All prior vehicles have had an accessory fuse that I could use that only has
>>power with the ignition on. I cannot find a fuse thus far that is similar.
>>I have it piggy-backed on the cig-lighter fuse now, but it's always on.
>>
>>Question: Is there a fuse in the accessible fuse box on the S4 that is only
>>on when the ignition is on?
>>
>>Thanks,
>>Keith
>>
>
>http://www.bentleypublishers.com/product.htm?code=ab64
>
>I have the 2000 model's CD, and I'll look it up if I could find it,
>but the connection points probably won't match the 04.
>Note that the electrics in this are CAN bus controlled, where carious
>devices sit on a data bus with power leads.. The central controller
>tells the remote device (interior lights, etc) to connect, or
>disconnect from the bus. This means that it might be had to find an
>"on with ignition" wire in a place like the sunroof control panel..

The presence of CAN bus controlled functions doesn't mean the power feeds are
all commoned. There is still a fuse panel with lots of pretty colored fuses
and there are still plenty of circuit breakers, both used to subdivide the
power into manageable domains while assuring no single fault can take the
entire car down.

To the OP: unless it has gotten a lot more difficult to route a wire up the
A-pillar and under the roof trim emerging at the mirror stalk, just use a DVM
on the fuse panel and find an appropriate fuse to tap. Start with the rear
window defogger fuse...

/daytripper
'00 s4 6spd