It is x502 pin 16 and 17.
I have both wires on the bulb.
It´s looking like that:
12volt Batt. ===> 7.5amp Fuse ===> 2Watt bulb ==> Both wires on x502 pin 16&17
Both wires go to EML and during the Test EML will connect them to 0 Volt/Ground/Chassis ...
(i´m writing too slow..... )