Originally Posted by
fraser9764
i may be wrong but its not a switch, its the excitation voltage, i'm ot 100% certain how the wiring works without studying it so i'll let someone else explain...
yes i believe that your correct its called the excitation voltage, however for the ign / battery light to illuminate in the first place the altenator must act as an earth? and it doesnt seem to be doing so, however im not sure if a certain rating of bulb is required etc?