Why do automotive relays have an odd numbering system?

For example - a 12V relay would have spade terminals labelled as '; 30 85 86 87 87A ';





Why not stick to something simpler like C1 C2 I O1 O2 ?


(Coil 1 coil 2) Input - Output 1 Output2 ?)





Seems more sense in this than 85 %26amp; 87A.





Why is the odd numbering system now common ? %26amp; where did it come from ?Why do automotive relays have an odd numbering system?
The numbering comes from a DIN standard for wiring. DIN, an acronym for the German Deutsches Institut f眉r Normung (German Industrial Standard





DIN 72552 specifies terminal ID and function





The purpose of the terminal designation system for automotive electrical systems is to enable easy and correct connection of the conductors to the various devices, particularly in the event of repairs and equipment replacement.Why do automotive relays have an odd numbering system?
Don't you have something more important to worry about?





Component (any type of component) numbering is arbitrary and totally up to the manufacturer. They can use any scheme they want.








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