elie: If I'm reading you right, then I'm not sure I agree with you. If you wired from green wire common point, through the switch to 85, and then 86 to negative, you've still got a forward biased diode -> big current flow and popped fuse.
If you have that relay, then 86 must be connected to positive via whatever switches and fuses, and 85 must be connected to negative (again via whatever else). That way the diode is reverse biased in normal operation, and only conducts as the relay deenergises and creates a back EMF.