When I flip up the headlights the fog light (center) works but I can't get the low beam (outside) or main high beam (inside) to work. It isn't the bulbs (already checked that), and when I checked for signal I wasn't showing any voltage even after all of the lights were on. Although I'm not overly familiar with this car I believe I had all of the switches on because the dash showed all three lights activated.

If it makes a difference its a jap-spec 850i.

Is this a common problem that is an easy fix???

One other thing I forgot. The mirrors seem to be stuck in the down position...

If I select the left mirror I can adjust it like normal, but as soon as I stop adjusting it the mirror tilts all the way down. Both sides react the same. When I select either side the mirror automatically tilts all the way down. Once the mirror is titled all of the way down the motor doesn't stop, it continually tries to move the mirror farther down for a short while, then it stops.

This gives me two problems. First, I can't use either of the side mirrors (unacceptable), and second, I'm afraid the motor in the mirror will burn itself out...

Ideas?

Have you checked all of the fuses in both the front and rear fuse boxes?

The rear box is on the left side of the trunk behind the side panels.

Unplugging all the relays and fuses one at a time and plugging them back in solves a lot of contact problems as well.

Rebooting the car by disconnecting both batteries helps with crazy computers as well but be sure you have the radio code if you have a stock head unit.

I agree with Terry as far as checking fuses and reseating the relays is concerned. It is also possible that the headlight harnesses have cracked or broken insulation and are shorting out the low and high beam lights. I repaired a harness with that very problem yesterday. You would need to remove the entire headlight assembly to access the harness and make repairs. Not a big job if you know what you are doing.
Mirrors are a different issue and would have to see what you are experiencing to help out. I do have spare mirrors and could ship you one to experiment with and eliminate (or confirm) the mirrors on the car as a problem. If it is not the mirrors themselves (unlikely) it is quite possibly the controller.
We have a good J-spec owner in your area (Calgary) who has helped other owners sort out their problems. If you like email me and I will forward you his contact info.

I got the inside highbeam to work by re-inserting all of the fuses... Now for the relays and maybe the lowbeam will work.

With HID these cars would have a pretty crazy set of lights... HID for both high beams and the fogs..... Anyways, I digress.

As for the mirror thing. I might just take a video to demonstrate the problem...

This is a movie of my mirror problem. As can see, whenever I select a mirror it turns to the bottom. I can still move it, but whenever I stop making an adjustment it reverts to the bottom again....

youtube.com/watch?v=hKOcmQP1rCk

or search for "850i mirror problem"

In the schematics for the '91 and '92 850i there is only the switch and the mirrors in the circuit along with fuse F12 in the front fuse box.

I would pretty much bet on the switch.

If you set a mirror and turn the ignition off does the mirror stay set?

If you set a mirror and flip the selector to the other side, does the mirror stay set?

If you set a mirror and turn the ignition off does the mirror stay set?

Yes

If you set a mirror and flip the selector to the other side, does the mirror stay set?

Yes

I'll double check the fuse again i guess...

So that you can drive it without being paranoid about burning up mirror motors:

Set one mirror and switch the ignition off.

Switch the selector to the other mirror and turn the ignition back on.

Adjust the second mirror and switch the ignition off.

Both mirrors should be set now--disconnect the connector from the switch(s) until you can find a new switch.

Unfortunately the fuse covers too many other things to just pull.

Email Wuffer--he may have one (wuffer.net for contact info)

Well... I was incorrect the first time. When you shut the car off the mirrors still do revert to the down position. It got the best of me so I pulled apart the door panel, dismantled the switch assembly and cleaned it. Now the mirrors work fine.
New problem. Took the car in for the out of province inspection and they weren't able to find the vin... Needless to say without a vin I failed the inspection.

Where is the VIN on a j-spec 850i?

IIRC There is always supposed to be a stamped VIN between the wipers.

Some Euro cars have it on the passenger side fender about where the headlight assembly is. And I have also heard of it being under the passenger seat.

Three places possible. Under the fuse box lid, at the base of the windshield, below the passenger side wiper stamped into the metal and har to see (open hood) and sometimes on the E-Box on the passenger side firewwall. It is also on a tag on both DME's.

Thanks for all the help so far guys. I grabbed the VIN and passed the inspection even though the low beams still aren't working.

Any ideas on what would cause a slight vibration (for lack of a better term) at about 1600-1900 rpms? Gets worse under harder acceleration. It acts the same in every gear. It doesn't appear to be speed related. Ideas?

I'm not sure if it is a vibration or possibly the engine missing at that rpm. My brother had a similar problem in his lexus and a set of plug wires fixed his problem... I don't have enough experience with the v12 to correctly diagnose the problem...