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

Found one. It was the back-up lights, etc. that was switched.

Thanks.
Keith

On Thu, 09 Sep 2004 21:21:58 -0400, Doug Warner <dwarner22 (AT) ccharter (DOT) net>
wrote:

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