I have removed the cluster on my RT in order to address a few issues, namely a misaligned odometer problem and a dead hi-beam bulb, and just for some general maintenance. I plan to take the cluster into my local speedo shop (APT Instruments) along with a copy of the fine repair article found on the airheads site. I plan to replace the bulbs in the cluster with all LED lighting unless someone can give me a good reason not to. I would like to be able to give the shop some sort of pinout diagram to aid in bench testing. On my cluster (looking at the back) there are 12 spaces for pins that correspond to the harness which is numbered. There are 2 vertical rows of pins which in my case have actually 5 pins per row. Number 1 on bottom right (again looking at back of cluster) is just an open hole and 2 through 6 are occupied by pins. Number 7 (bottom left) through 12 have pins with the exception of 9 which doesn't even have a hole for a pin. The Haynes manual schematic was no help, however my original owners manual actually has a little block diagram which shows that pins 2 through 6 are voltage for neutral indicator, voltage for tach and speedo illumination, generator light, turn signal indicator via flasher, and oil pressure light respectively. Pins 7 through 12 either tie into what appears to be the flasher unit (the symbol is sort of a 5-pointed star with one line having an arrow) which is presumably elsewhere on the bike (headlight bucket?) or in the case of pins 1 and 7, tied internally across the hi-beam indicator. Although I've seemingly answered my own question, I'm still not certain where one would attach ground when testing the various indicator lights. It is not readily apparent from the block diagram what the actual ground path is. Sorry to be so verbose, but can someone clarify this for me for purposes of not letting the smoke out when bench testing?