IAC VALVE AND ALTERNATOR

I have a 2006 ford Taurus SEL. Ok I just had my IAC
valve n throttle thingy done due to the gas was
accelerating REAL high too where my rmp was
3000 insted of its regular rmp.so to make a long
story short. I put it in the shop and I got my car
back it had a jerk stall like it hesitated even when I
put it in reverse it has a jerk motion like it want to
cut OFF. Now with my alternator I ordered it off line
it works fine up until I had put my car n the shop
for the throttle situation. They told me it wasn't
charging the alternator but all of the sudden when I
went pick it up it all of the sudden charging. Help
HELP