im hoping i am allowed to post this here as i am desperatlly in need of some guidance, i also have the no bus issue, i have replaced ignition switch, PCM, ground and posotive cables, connectors to battery, battery, checked all relays and fuses , tested all grounds etc.... truck starts and runs fine but i have no break lights ( tail lights do work) no turn signals, no dash activity except foe all warning lights, no wipers but , after driving it for about 15 mins everything comes on and works and will continue to do so untill i park and shut it off for more that half hour. then its same old thing once stasrting it again, no activity for the first 15 bmins or so....i had alternator test it passed also.. 2003 dodge ram 1500 slt 4x4 5.9L magnum.. PLEASE, i am at a lose..yes i did hard reset on it and relearned the computer. also when i hook to scanner it doesnt even read truck at all, i did the c code thing on truckand got several codes but they all pretty much point towards everything ive fixed. bought PCM from reputable source and it was programed for my specific vehicle and VIN.any and all help will be appreciated as my mother has stage 4 cancer and i take care of her and its my only vehicle and weith this issue i cant drive at night cause break lights or in rain cause no wipers etc...thamks again

 

Probably more than one problem.... Brake lights, turn signals and such is likely the multi-function switch in the column. The No Bus means the cluster is communicating with the PCM, and the diag port isn't either apparently. Unfortunately, there is a whole host of things than can take down the communications bus.... in your case, I would suspect a bad wire somewhere... since the engine runs....