Someone gave me an old Sun Super Tach II that was working fine when pulled. Sadly, the original owner lost the original wiring harness (4 wires) and nicely soldered four wires to the posts at the back. Even more sadly, all the wires he used are red!! So I have no idea what goes to where. I can see some small letters near the posts that look like G, I, L, and maybe B. Does anyone know what they mean? Thanks!