Fuse #23, No it is not the red/gray wire and the HU has been in for 8 months.

[AtlBMW]

So started blowing #23 and have now been through 2 packs of fuses during diagnosis. Red/Gray in the dash has a connector but is connected to another red/gray and continues in the harness. It is not connected to the head unit. Promise.

The plot thickens. At first I could turn on running lights and no pop. Only once I pulled the switch all the way out and turned the headlights on, did I get a pop.
Than after some pulling bulbs, inspecting connections, cleaning etc. I could pull the switch all the way out, running lights and headlights and not pop. Only when I started the car did I get a popped fuse.

Than I pulled the right license plate light only to find the the brown wire is not connected and it appears the the unprotected connector is flopping around in the fascia. BINGO I think!
So attach connector, and now the fuse blows as soon as I pull the switch to the first, running light, position.

Like I said I have tried to systematical trouble shoot this puzzle but I am tired of buying fuses as well as making things worse.

Any advice?

[AtlBMW]

Nobody? I do have a multi meter but don't know how to use it..

[ErikVonVicious]

well Ill bite...so it doesn't blow unless the ignition is on? its all lights on 23 if I remember, that makes me think its headlights or dash lights, since you can turn running lights on without the key in but headlights don't work unless the ignition is on. or you could have a damaged wire under/behind gauge cluster that makes body contact and only receives power when the light switch is pulled AND the ignition is on.
does every bulb work in your cluster? including the ones that just light it up orange to see the gauges?
since your already pulling bulbs yank them all for 23 and turn everything on, if it still blows you know its wires somewhere before it gets to the socket since no bulb is like a 2nd off switch/cut in the circuit.
if it doesn't blow then just start adding bulbs still with switches on until you add one and find it blows the fuse when the circuit is closed.

for the multi meter heres a quick search link describing basics

http://autorepair.about.com/cs/troubleshooting/a/aa063001a.htm

the brown wires are almost always a ground connection so even if it were loose and contacted body somewhere it wouldn't pop a fuse since the whole body is probably already connected to that ground wire(if you have clean ground contacts still). BUUUUUUUT if you connected it wrong then you could have connected a positive directly to body ground( since some of those sockets use only a positive wire and use the car body for negative) so when your switch gets turned on its just like you shorted a piece of wire from battery positive to the frame, that would for sure blow a small 7.5 amp fuse or heat the shit out of the run of wire if a larger one was put in by mistake (proper fuse always costs less that a fire hazard)

[AtlBMW]

Thanks for the response. I thought I had it, with the front park/blinker bulb. The bulb with 2 large contacts appeared to be crossing the 2 connectors in the fixture. Changed bulb, pulled switch one click, no pop. Two clicks, no pop. Start car, no pop. Yea!

Just ran to the store and pop. Oh well I feel I am closer. At least I feel it is in that fixture, although it is a bitch to get at as I have late model bumpers.