Weirdest E30 problem ever?

[packratbimmer]

Anyone want to take a guess??? I have to share this strange event that happened a few weeks ago that I diagnosed within an hour, but crossed my fingers a while because it was so weird. My 325i is a very stable car that I daily drive, first of all. So a little while back I was cruising along as usual when the check panel in the visor threw both the license plate light and the tail light light - HMMM I said since both happened at once (it was during the day and no lights were on BTW). Well, after a few minutes I needed to use the left turn signal and it started the rapid blinking thing that is usually associated with one bulb being blown. After returning home I was surprised to find that the rear tail lights, license plate lights and the blinkers were all working, but both of the left blinkers were flashing fast like a bulb was blown. Yes, I was also thinking FRIED wires or hungry mice had been at work, but I guess not since it has been fine for weeks. One more clue: The flashers worked perfectly at the normal rate. Any takers? One part fixed it...I hope!

[roguetoaster]

Only related part I can think of in near proximity to the rest of those systems would be the trunk light switch or the trunk interior light grounding on the body.

[packratbimmer]

roguemaster, Great ideas, but those were not the fix. The first thing I swapped out was the module for the check panel in the visor panel, but that did not work.

[roguetoaster]

This like the r3v version of Stump the Chumps on Car Talk. I like it, but not enough to write my answer on the back of a $20 bill.

[varg]

Check your grounds. The ETM will show where the grounds are for that circuit. Also check the bulbs for a broken filament. I've had a broken filament cause an intermittent hyperflash because the bulb was oriented so that the filament could still make contact, but would get jostled loose by bumps.

This like the r3v version of Stump the Chumps on Car Talk. I like it, but not enough to write my answer on the back of a $20 bill.

That was the puzzler. Stump the chumps will be when we call OP back and see if we fixed his problem. The other gag was to either write your answer on or send in [insert piece of expensive equipment or rare car part] IIRC.

[packratbimmer]

WE HAVE A WINNER!!!! VARG CRACKED IT!!!!! > The left front bulb was causing the mayhem. I swapped it and a few weeks to a month later, all is good.

[savannasanders]

That's one strange car mystery you got there! Based on the clues, my guess is a faulty turn signal relay might be causing the weird blinking issue. Fingers crossed that's the culprit and it's an easy fix! Good luck!

[packratbimmer]

Absolutely zero issues since the right front dual filament bulb was changed out. My multimeter is kaput or I would see if it is shorted internally.

[jeffnhiscars]

I had just left town on a road trip so was only about 10mi from home. I stopped at a traffic light and the car just dies...as in dead.... No dash lights no ignition response. I had it towed for the very 1st in an e30 and I've been driving at least 1 since I bought my 1st in 1997.

what I ultimately discovered was that when I replaced the reverse light switch after my 5spd swap one of the wires was not pushed on far enough. It worked loose, grounded itself to the drive shaft and took out my main fuse. Replaced the wire and the fuse and problem solved...just cost me a tow and a rescheduled trip.

[ZeKahr]

I haven't had OP's same electrical problem, but mine has also had strange shit go on electronically, mainly with the reverse lights. First, fuse 10 wouldn't stop blowing. Then, one rainy day, when I put on my right blinker my reverse lights would all of a sudden start blinking along with the right turn signal (this didn't happen for the left turn signal though). I tried tracing the wiring short, accidentally broke the clips holding the back trunk plastic, lifted the rear seat (I think the tail light wiring routes through here), didn't see any chafed wiring, got frustrated and just pulled out the reverse bulbs.

The wiring in these cars, if it hasn't already been overhauled, is getting old and has lost quite a bit of its tensile strength. Not so much an issue for the heavy gauge wires, but the limp wrist noodle 18-20 AWG wiring BMW used in places like the reverse lights and the gauge cluster (and probably other areas I can't think of) is pretty damn fragile.