Unhook your RPM/HOURMETER and I bet it quits. Its a known problem with these machine. Mine just stay unhooked till temps stay above the 50's. I just unscrew it where it goes in the dash, right above the battery. Then tape the nut so it doesn't slide down the shaft. Should only happen in freezing temps. People have tried changing the grease and oiling the cable but as far as I know there is no cure.
Rich