If my memory is correct when the war in Ukraine began most or all Deere planter harnesses were made there.  For quite a while there were literally none available in the world.

A few years ago we bought a used 24 row 1770.  Backed it in the shed, went through it checking bearing etc.  Pulled it out of the shed to unfold it and the computer smoked.  It was a Gen 1 computer, NLA. Maybe if you're lucky and do some searching a dealer would have one on the shelf. Or we can upgrade to a Gen ... 3 I believe.  OK, it's planting time let's go fastest way.   Well, Gen 1 is three boxes while Gen 3 is one box.  So we had to have a cable custom made (Ag Electronics?  Been too long) to connect it all.  Oh, and this is hooked on to a red tractor instead of a green tractor?  Hmmm...

Over the time I owned it I gave more for repairs than I gave for the planter.

Many years ago we had an IH HRF 900 Cyclo.  Kept fighting electrical problems.  Finally traced it down to a 4 foot section of one wire.  Cut it out and soldered in a new one and solved our problem.  Talking with a service guy he said the problem is when the supplier is making the wire they runout of conductor.  So the stick a new conductor in and keep going.  While it's new it tests and works like it should.  Over time corrosion and wear cause contact to be lost intermittently.  It won't stay broken so you can find it.