ISUZU RODEO PROBLEM - Somebody please help me

1999 Isuzu Rodeo 2WD 3.2L Manual gear shift. Engine running fine but "Cruise Set" light comes on by itself and the engine hesitates like a solenoid is coming in. Sometimes the light does not come on, but for no obvious reason it will come on, and sometimes it will keep coming up making the vehicle undrivable.
My main problem is that I live in Lagos, Nigeria, and the local GM dealer does not have full diagnostics, especially as my vehicle was imported second hand from USA. Has anybody had this fault, which my Nigerian mechanic reckons, is a wiring fault, being intermitant and showing different codes including P0566. I have physically checked the cruise control switch on the column, which seems ok. I have been trying to solve this problem since before Christmas. Jim