Brakes problem
2001 Ford Windstar 6 cyl Two Wheel Drive Automatic 149,00 miles

I just recently put my car in shop. I bought the car used from a mom and pop dealer I also bought the exstended warranty.The fuse that runs the A/C,Heater,Odomiter,Speedometer and the o/d light on the dash blinks.The break light stays on the dash also.When I put the a/c on or the heat,I can tell the motor are working,but there is no cold air or hot air,just air blowing.The Amco transnmition guy said that I need to replace the Electric unit(under warranty) along with the Hydraulic unit (not covered)along with the pressure switch(not covered).My question is would this make my heat/ac/odometer/speedometer fuse blow?Please help with my $800 dollar question.
Thanks,
curt