Instrument Cluster Troubleshooting
 

1990 325ic and the left turn signal indicator n the instrument cluster does not illuminate. The turn signal works, the flasher clicks, and I have changed the bulb, even swapped out the bulb from the right side indicator that does work and still she is blank. Do I need to pull the back off of the cluster and re-flow the solder to the bulb socket?

Yes. Take the cluster out. it's not too difficult. I advise taking the steering wheel off first. And take the cluster out. It will either need new solder or a new motherboard.

Mine did the exact same thing. I just replaced with an ebay motherboard. And it works perfect.