Nice to answer to a question posed by Boxer !!!
On my 308 from 1979, it is written on the manual that the yellow one is to warn that the fog lamp is on. I don't have some on mine so I never saw it lighting. I didn't know that it was all aux. lamp control. I just have the wiring diagram here, the caption are in my owner'book in my car. It goes from panel to an item name 114 to tunnel (free without switch on mine)) and to signal lamp tail rear left... If yours have been modified and if it's running by itself, there must be something wrong with fuse box or with the consol harness... hope this incomplete information could help... Good luck or buona fortuna (italian car electricity....)
308 GTB 1979
Last edited by Jephma; 09-10-2007 at 12:05 AM.