1997 chevy s10 4.3 vortex
So it won't restart with the A/C on? Does it crank over or not do anything? From what you have stated I can only assume that the engine is so tired that it can't drive the A/C right off the start. Maybe you can give a little more information.
Truck has no problem turning over but will not restart.
Ok that sounds like some thing is pulling too much electrical power or there is a feedback through the A/C power circuits. Check too see if there is a resistor or a diode in the power wire to the compressor, it could be bad. Also check the A/C relay and make sure it is not sticking closed when the key is turned to the crank position. That is about all I can think of right now.