2000 Expy with 4.6 and 4wd....having a problem with my air bag light! The light flashes at startup and then runs constant. This happens about 95% of the time...sometimes it stays off. One time before I took it to a dealer and they replaced a resistor somewhere on the passsenger side and the problem was fixed. They told me that is was fairly common and that it would probably need to be done again. I am a fairly good competent at soldering...so I want to fix it myself! But I cannot find what they were talking about. Bought Hayes manual and doesn't mention anything? They said it was something to do with the seat belt sensor on the passenger side and that it was somewhere around one of the passenger side doors? Anyone know....?

Thanks!!