in answer to the original question, we took a leaf out of frank masseys book so to speak and ask customers to allow us 2 hours for the diagnosis and possibly the rectifiation of the fault.
If in this time we cannot sort it we then get back to the customer.
we have found that most general faults get fixed in this time, but we do assure the customer that if we only take 1 hour then this is what we charge.
by the time you have got the vehicle in, test kit set up, wiring diagrams or tech info sorted, you need this time, or you are forever on the phone to the customer.
we also explain that if they pull the plug they still have to pay, i would say that 95% of customers are happy with this when you explain the complexity.
remember the code is the end result you still have to find the fault.
ATB
Nev