thanks axlrose & rhandwer.
right now the truck is frozen solid and covered in 40 cm of snow, and it's always dark.
at first opportunity i'll remove both positive and negative cables for 'microscopic' inspection. i'll also make sure all connections are clean and tight.
and i'm buying a new battery with lots of cranking power. the old one is old and weak. the solenoid to starter wiring is also coming out for inspection.
i'll post my findings.
regards
opcorn: