About a week after I put in the RF separates in my doors (5 1/4" and a tweeter) the tweeter hasn't worked on the drivers door. So, now that I've had my door panels off for the past three months (Shaving door handles, putting on SS mirrors, going to paint next weekend) I finally looked into what might be wrong. All the wires were still attached, tested the tweeter by connecting it to the pass. side x-over (These are the x-overs that come with the speakers) and it worked fine! I took the cross over apart expecting to see abunch of caps and maybe a coil, sure enough those were there, but there was also what looked like a dome light! The filament wasn't connected inside, so I made a jumper wire and now the tweeter works! So, what's the deal with putting a light bulb in there? Is it supposed to work like a fuse to protect the tweeter? There wasn't a bulb "number" on it to replace it with, so I just left the jumper wire in there. Any body have any ideas?