My knowledge of this stuff is still quite inexperienced and it doesn't help that I don't have a wiring diagram either.
Anyway, I haven't attempted it yet since I'm still waiting on some more parts to arrive.
So... here are some of my questions.

I've been searching all morning and found the Alta gauge instructions.
They're saying to tap into the DSC gray w/ red striped wire for illumination.
My car doesn't have DSC so... will that be a problem? Is that wire still there?

My other question is...
from the searching I've done, some people have tried an add-a-circuit alternative rather than tapping into the wires directly.
Some of the threads I've read are saying that Fuse #42 is the 12V power.
Some are saying that Fuse #42 is the acc./ign. power.
I actually haven't looked at my fuse panel yet, but if #42 is the cigarette lighter fuse, wouldn't that be accessory power and not 12V?
To those that went this route, which fuses did you use the add-a-circuit for and with which wires (12V/acc/illumination).
The only thing I know for sure with this is that the screw in the fuse box is the ground.

Thanks guys!

 

Gray/red wire should still be there. I used fuse #32 for an add a ckt. #32 fuse is for backup sensors which I don't have. Good luck.

 

SMOG, a member here, has a pictorial on his website on installing gages, including wiring.

http://www.mini4fun.info/09_MCa_Gaug...6_Photos..html

Dave

 

Thanks you guys, I appreciate it.
That's some good info, especially SMOG's write-up.
Gotta love the pics.

I do have rear backup sensors on my car (I got those for my wife and she still managed to reverse into something... ) so I can't try it directly...
I'll try it from Fuse 32 with maybe something like this:
http://www.amazon.com/Littelfuse-FHA...=pd_sim_auto_1

 

I've been doing a bit more research and I've always just tapped into circuits for these kind of installs on other cars, so I think I want to try the add-a-circuit method this time.

I've found some new things out though.
Fuse #32 doesn't look like it is for the backup sensors.
According to the diagram, it looks like Fuse #30 is.
http://img69.imageshack.us/img69/6647/f30pdc.jpg
I believe I'll use a different fuse though since I have PDC.

I'm thinking about using Fuse #9 for 12V power because the fuse is located before the switches
http://img638.imageshack.us/img638/1132/f9doorlocks.jpg
or Fuse #40 since it's a straight to power and I don't have seat heating.
http://img593.imageshack.us/img593/3...erseatheat.jpg
For the gauges with the add-a-circuit, probably a 10A fuse for the boost and temp gauge would be fine, right?

And like the others, I'll probably use Fuse #42 for the accessory/ignition switch power.
http://img13.imageshack.us/img13/2323/f42lighter.jpg

What I still don't understand is why many others use DSC for night time illumination. I'm gonna try to add-a-circuit to Fuse #16 to see if it actually works.
http://img832.imageshack.us/img832/9490/f16dsc.jpg
If it doesn't work, then either the others were wrong about tapping to the DSC or it's something after fuse that caused it to work with illumination.

IDK... what do you guys think?
I found these wiring diagrams over at BMW-planet.com.
Are they accurate?
Unfortunately, a lot of other stuff was missing on the site, but the Fuse diagrams were still there.
What would you guys do differently than what I had described if you wanted to go the add-a-circuit route?

Thanks!

 

The DSC light is an LED and it takes a special circuit to dim them, that circuit is already in the car for the stock instrument lights and the DSC light is a convenient place to tap into that dimmer circuit. The cigarette lighter socket is switched power and Marshal gages require a switched power source, again, it is in a convenient place to tap into.

Dave

 

Fuse diagrams can vary from year to year, very possible what works for me is different than yours. Does your fuse cover have pictograms?
Somewhere around here is a thread that gives you an idea of what is always hot and whats hot with the key on, I'll try and find it.
That gray/red wire (DSC) under the shifter console is for illumination. I tapped into it to provide lighting for a couple of aftermarket guages I added. Good luck.
In the electrical threads it's a sticky "Hot or Not" hope it helps.

 

AHHHH!!! Thanks for clearing that up.
It's a DSC light wire you're tapping into, not the actual DSC.