My 03 dodge cummins with a 6 speed manual is the base model without cruise control. I added cruise buttons thinking this would give me cruise. well long story short its not working. I checked each button and plug with the volt meter and researched to no avail. checked codes with an obd2 scanner with nothing. did a drivetrain check with cycling the key and only found a code after doing the chassis code check by holding the tripometer down and cycling the key to on. the code read "" AC 30" AC on the left side of the screen and 30 on the right nothing between them. all my research says the code doesn't exist. any help would be appreciated on either the code or fixing the stupid cruise!!!!! thanks again and sorry for being long winded

NOTE: the manual cummins DOESNT have any cables or vaccume hoses that controls cruise. its all computer so please don't bring up vaccum leaks

 

I suspect you need to tell the computer to enable cruise control...... May want to chat with the dealer service department, and see what they have to say.