Liebherr 631B track loader electrical problem

I have a 1992 Liebherr 631B loader, made in Germany with a Mercedes engine. Tough machine. Very little problems. Recently it would not start except by jumping the starter relay positive and negative terminals with a wrench and simultaneously turning ignition switch to start. Replaced the relay. Should have known that wasn't the problem because the electrical system would not shut down without jumping the terminals again without turning ignition key to start.
There must be another relay somewhere. My suspicion is it may be connected to some safety feature.

Does anyone have any ideas? Thanks.