In my 240 1991 Wagon the seat belt reminder light never worked. Got it in to my head that i would fix it since I had to tighten handbrake anyway. Seemed easy enough; someone (who was obviously not a fan of seat belts or blinking lights) had simply snipped of the wires coming out of the seat belt buckles. System seems simple enough, quickly wired up driver seat buckle; grey wire out of buckle connects to read&white (12V) wire (which also power small lamp over ashtrey), read wire out of buckle connects to brown wire (7V?), and finally connected a ground wire. Works fine, seat belt reminder light flashes untill seatbelt is put in buckle. So far so good now for the passenger side and things stop making sense. Power in easy enough; there is another grey wire (12V), and another ground - no problem. But then the last wire... 2 posibilities here: The first is to connect it to the same brown wire as the driver seat buckle (which is actually split seemingly inviting this possibility). But this means that the warning light dosent go off untill both front seat belts are buckled. Even when driving alone! The second option is a yellow wire sticking out of the carpet. This also have 7V so that might be right....No, when connecting the last wire in the passanger seat buckle to this yellow wire, a rather unpleasent buzzing sound emerges from deep with in the dashboard, and there is no flashing of the light.
Ok these might not be the most exciting questions but I just cant figure it out: 1) I would really appreciate if someone could take a peek in their working volvo seat belt reminder light and tell me where the yellow wire goes.
2) The flashing light flashes about twice as fast as the turn signal lights (just as the remaining turn signal lights does if one of them is disconnected) - should this tell me something?
3)Could it really be that the passanger seat belt have to be buckled when driving alone - no pressure pad or something?
4)This manual (http://new.volvocars.com/ownersdocs/1986/1986_240/86240_01b.htm#pg24)says that the flashing will eventually go out after 4-8 seconds and that the reminder light is accompaniged by "a chime", neither happens, the flashing just goes on - even if it is just the passanger seat that is not buckled. Just if that tells someone something.

Appriciate any help - driving me mad that i cannot figure such a seemingly simple repair.

Chris