UPDATE,
ok after paying attention this time in more detail. the C/C only shuts off when I am in 5th gear and going up a major grade, like a 6 or 7% hill after a while bang. so I am thinking it is maybe some sorta speed/RPM thing because if I put into 4th and run a hill it will hum in C/C the whole hill.
Rich

07 Mercedes GL 450
93 Freightliner FL 70 C/C 8.3 cummins, allison auto
96 Toyota T100 4x4 xtra cab v6 5 spd
05 KZ 41kx2 NV Toy Hauler 14'garage 43'of 5r
04 polaris 500 HO 50th year limited
02 polaris 500 HO
51 willys M38
56 Dj