1998 Dodge Dakota Cruise control inoperative

The cruise control worked fine when I bought this used truck, but began to experience intermittent issues. Sometimes it worked while others nothing. The system always turns on when I press the cruise on/off switch, but it has progressed to not engaging at all now. So it currently will turn on, and the cruise light in green illuminates on the dash, but it will not engage at all. I did have an engine code of p1595 but I reset the codes and it has not come back yet but the cruise is still inoperative. I took the plungers out of the servo and cleaned them up but still nothing. I would greatly appreciate assistance because I cannot afford to start randomly replacing all of these parts in a hit or miss scenario. Thank you, in advance, for your response.