I have noticed a relatively minor, mostly aesthetic problem with my new-to-me 2003 WRX wagon. About 50% of the time, my front Running/Parking lights, the ones located in the Bug-Eye light cluster, stop working. Usually it is one side or the other that is out but sometimes it is both, sometimes they both turn on just fine. All other lights, including the headlights, fog lights, and side running lights work great. I've popped the hood and noticed a wire on the driver's side that is somewhat loose (I can sometimes hear it rattling against the battery) and wrapped in electrical tape but the connections seem solid from what little probing I've done. Additionally, I don't think this can explain the issue with the passenger side light. I've checked all of the fuses in the driver's side fuse-box and they all seem solid. Having spoken with the previous owner, he theorized that this may have been caused by the owner before him (I am the 3rd), who supposedly had a boost-gauge installed before he sold it.
Does anyone have any ideas on what might be the cause of this? I'd really like to fix it myself but I'm not entirely sure where to go from here.