Yep, I certainly do. If you are not properly equipped to fix the
problem, you charge extra for your incompetence.

Not everybody uses a warehouse sized semi for a service truck. I carry
enough parts on my truck to be able to effect permanant repairs 24/7 90% of
the time. If I get called out at oh-dark thirty, on a Sunday, or holiday,
your damn tootin I am gonna charge the OT service call just to come out, and
charge 'em for the regular service call if I have to go back with parts I
had to get from the supply house.

As a rule, if I don't have a part on the truck for the repair durning normal
work hours, I don't charge to go to the supply house to get it, and I don't
charge for a second service call.

I do *EVERYTHING* on flat rate, and the customer knows up front what its
going to cost before I make any repairs. The only variable is the
refrigerant charge. I can't tell them in that in advance until the system is
running and I put the thermometers, and gauges to it to see if the
refrigerant charge is correctly balanced.