Hold On.......

I just brought up that schematic and it is different than the other 124s.
The correct fuse on the Coupe is Fuse "B"..not 5..

But regardess, if you jumpered 1 and 3 of k38, that would eliminate K38 circuit ..
Did you take the relay right out and jumper ??...if YES, then
here is the next test:

Take k38 out and test for 12v at pin # 1 of the relay socket [ this would be where relay terminal # 87 would plug into ] WHEN the key is turned to start position...if NO, the problem is feed from the Ign sw.

Report that finding.

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A Dalton