just so you know: this is how a technician gets paid, if the book calls for the job to take 4 hours and you do it in 3 you get paid for 4. however if it says 4 and it takes you 6, you still get paid 4. technicians do not get paid overtime. most shops do not charge, or charge a cheap rate, for diagnostics. have you ever had to spend3 or 4 hours chasing a short, or a electrical problem, just to be told that the shop only charges 1/2 hour diag. since we do not get overtime or decent rates (most shops are over 80 an hour and the techs do not see half of that) get used to it.