hello,ill try to make this short, problem started with noisey shifting in and out of 4 hi ect after trany rebuild,tccm harness was roted so i replased it as well as the tccm,same thing was happing,now it wont go into 4 hi or 4 low light just blinks,then atc fuse blows,i pop in new fuse and 4button light says its in 2hi then fuse blows right away flowed with servise 4x4 ,with the tccm hooked up truck seem to be in 4hi with servise light on and no lights on the 4 button swith,when i disconect the tccm it goes back into 2 hi,,,checked vac lines front diff actuator,couuld thes be shift mortor,or transfur case problem,i have a ob2 scaner but it dont pull transfer case codes,its a 2000 blazer zr2 opp np8 with over 200000 km,and help would be muchlyyyy help full