Looks like the issue is solved. Some pins of the 4pin connector were seated slightly too deep. Once I remedied that, the forklift has been working perfect for several days.

A big thanks for the good info. It helps a great deal.

This forklift works so hard, surely it's on borrowed time given the age. I wondered what I'd do if the dash unit quit working. Replacement would be non-existent. My thought was to wire the solenoid direct to the fwd/rev switch. Theory says, each solenoid coil would pull about 2amps at 12v. Any reason why that wouldn't work?

Thanks!