[grouchyfungus]

A few weeks ago, the driver door lock actuator needed replacing on my 2011 E90 with 172K miles. Bought it from Pelican Parts, replaced, and everything was fine. A week ago, started getting a trunk open dash light when I started to drive. Also, pressing the key fob to unlock also opened the trunk. Three days ago, when I stated the car up first thing in morning, no dash lights, no speedo, and no climate control. I guessed that I blew a fuse. Looked at the fuse panel, three fuses were blown, 57 (I think, the fuse that goes to the dash), 73 (door locks), and 77 (climate control, glove box light, and trunk light). I replaced the dashboard fuse with a higher amperage (15 vs. the required 10) and dash function was restored. Upon replacing the door locks and climate control fuses, they immediately would blow. I started looking all over the car for a broken wire, or wire touching the chassis. Nothing. So I unplugged the new driver lock actuator and replaced the fuse. After pressing the key fob or internal lock, the fuse blew. Replacing the climate control fuse, the fuse blew, even without starting the car. I bought a new battery, no change. Last night, I decided to try to unplug things on the circuit in question and plug them in one by one in a attempt to find a fault with an actuator or light. After different iterations, I encountered a serious problem. I had driver door and passenger door lock actuators unplugged, and the trunk latch actuator unplugged as well. I replaced fuse 72 (door locks) and, when I replaced fuse 77 (climate control), even though I've done this many times before, the windshield wiper pump began shooting fluid, would not stop, and expelled so much fluid behind the dash that the fluid must have seeped into the cabin and behind (or above) the fuse panel. Smoke and electrical burning odor came pouring out. I panicked because it was so unexpected (for me). I tried to pull the climate control fuse out but couldn't find it easily with the smoke. I ran around to the driver side and stated the car to see if I could shut it down from there (I didn't know). I had the trunk open and the battery cover off so I decided to just pull off the positive cable (rather than the negative, duh!) I scrambled to find the right size socket (of course it wasn't right there). Meanwhile, the pump is still going and the head and tail lights were on as well. I found the socket and pulled off the positive cable and the car shut down. I was seriously pissed that this happened, after multiple times of doing the same type of thing with no adverse consequences.
After cooling down, I reattached the positive cable and same thing, so i disconnected the negative cable, and put the positive cable back on (car is off).
I checked the fuse panel and no more fuse were blown, only the ones as before. I also don't see and melted wires, burns, etc.
The car starts and can be put into gear to be moved, I won't dare drive it like this. However, the car doesn't turn off with the key, only way to shut off the car is remove the positive cable. I know we're not supposed to do that, but I didn't know what else to do. The key stays in the slot and cannot be removed (no power to remove it). If I let the car run (wiper fluid pump is still going but no fluid), after a minute or so, the head lights flicker and it sounds like the engine revs. No dash lights even with dashboard fuse not blown.
Appears that an electrical module is definitely fried, but I don't know which. Fuse panel appears fine. Wiper fluid pump may be burned out (but I can hear it running). Battery is brand new. Interesting that the car turns over and can put into gear, but then again, I didn't want to run it too long. Also, nothing was touched on the steering column nor anything done around head and tail lights.
Any idea what happened? And what's now needing replacement?
I plan on towing it to the dealership as soon as convenient.

[grouchyfungus]

For anyone who might experience a similar issue, I solved the problem.
After taking it to the dealership, they told me what I thought it was, but only after tearing apart the underside of the drivers side dash/footwell, and other issues not related to the initial problem. I will say that the service advisors at the BMW dealership in Las Vegas, especially Dave Leslie, are exceptionally helpful.
Problem was the junction box was bad. I wasn't told this, but I now know why the wiper fluid went crazy and the panel was smoking. When I put in the fuse for the A/C, locks, etc. it was a 20 amp fuse rather than a 5 or 10 that was required. I didn't remember doing this but I was out of 5 and 10 amp fuses and I'm sure I said, "screw it, use the 20 amp." I'll never do that again! Of course, the shorted junction box (or that connector/PCB area) energized the wiper motor and, because of the higher amp fuse, didn't
t blow the fuse. Subsequently, the junction box starting burning internally. That is where the smoke was coming from.
I bought a salvaged junction box from a similar vehicle for $100 off of eBay. Made sure all the fuses were good and of correct amperage.
Put everything back together that the tech dismantled under the driver's dash/footwell, and installed the "new" junction box.
Car runs fine now, the key that was stuck in the insert was damaged but I had a spare key. I am surprised I don't have to program the junction box to my VIN, I thought it was a must.
All in, I spent $150 for fuses and a junction box. Dealer wanted $1600 for new junction box and programming, plus about $900 for diagnostic fee (which I'm sure would have been negotiable if I had them do the work).

[jbellk75rt]

Quite a tale. Glad you were able to effect repairs at such a reasonable cost outside of the diagnostic fee. Yes, overfusing when tracking electrical faults can be disastrous.