i was experimenting today and what i did was hook the test light to the positive battery cable and starting touching all the fuses. i got 3 of them to light up.. this is weird. ground never runs to fuses so why did the test light illuminate? anybody know?

 

I am sorry to say that i have less knowledge on these technical stuffs.may be some one else can answer you.

 

Its called residue ground and it can come from a relay, a electric motor of the door windows or wipers, Or a circuit. You should never use a test light ever. Your lucky that you did not burn something up.