The crews were bitching that the trim switch was not engaging. Without auto-trim, they basically have to hand fly the aircraft so the bitch was a valid one.
The switch uses a
solenoid
to maintain it in the "on" position. I found if it was held up just a tad bit longer than normal (a couple seconds), it would remain engaged. You could smack it and have it drop off (not every time, but just once is an indication that the switch is weak).
As par for the course with these older aircraft...... no extra wire to do your work. A couple tie-wraps to hold it out helped.
I treat these just like a multi-pinned cannon plug, Start at one edge and work your way to the other side. I care about making sure I get the connections right, but I care not the number order I do them in.
The replacement fixed the problem and the "yoke actuators" could re-enter their nirvana "auto" mode again.