As thin as a hair.

I don't know what gauge wire it would be but that Bosch starter relay must be assembled by Fairy's.  The coil wire is so thin it's almost invisible.  When I tried to start the R80 again I got nothing.  I traced it down to the starter relay and coming from a manufacturing background any thing that can be built can be disassembled.....and so I did.  If you look very closely where that blob of solder is you will see the end wire of the coil.  Corrosion got to it and with the heat from applying 12 volts the wire broke.  But I found that this relay was upgraded for the Volvo radiator fan to a better and stronger unit so not wanting to give Bob's BMW my hard earned cash for a stock Fairy built relay  ($30) I bought a better unit online delivered (in 5 days) for $14.00.  Hope the Fairy, Goblins and Troll's Local 763 doesn't find out about this!