It is akward indeed. Any slight increase or decrease to the voltage and you might encounter other problems. For example the classic problem of the airbag failure indication. It has to do with OHMS. The circuit has a constant of about 2.7 to 2.9 ohms. Any increase or decresae from that will result in the computer to detect a false indication regarding matters like that. Increase will diagnose excess air bag explosive material for example.
This is why a lot of dealers explain this as a falt of the cabling under the seats. When these do not make good contact all of the above occur.
pantelis
2002 Stilo 80 Active, no alloys, no power tuning, tinted windows, love the sky window though!