Hello, looking for troubleshooting assistance from those experienced with the ECM/BCM and general electrical. I have an '86 Eldorado. After sitting for a few weeks, I started it up and now have these symptoms:
* "System Problem" message.
* "Low voltage" light (engine data shows 0 volts at battery, even though battery is fully charged; I even swapped one from another vehicle for good measure).
* Gas gauge reads "E" and flashes, even though the tank is about half full.
* Turn signals will not flash, and the gear selector on the digital dash will not highlight the gear that has been selected with the shifter.

Seems to run fine other, though I have not driven far since this started. I should mention that the rear view mirror fell off & was hanging by the cord the day this whole thing started, but I don't think it's related. I checked all of the obvious things--bad grounds, fuses, etc. My best guess is that the BCM conked-out. Any other ideas? Should I just try a salvaged BCM? Thanks much.....Matthew