Yes, the solenoid is being energized. Just found out that the truck has been overheating and that when it cools down, the transmission does engage forward. We've been looking at the arrangement of the radiator and muffler on this truck and it seems that the muffler is too close to the radiator, provoking overheating of the coolant, especially in this tropical climate and a textile mill application.
Again I want to ask for any suggestions on how to solve what now seems to be an overheating issue.

Thanks,

ob_1