'88 Chevy wont start, all new parts

[spinne1]

Try this: get a long jumper wire with alligator clips. Attach one end to the starter solenoid post (the small wire place on the solenoid). Have the other end sitting loose near the battery. Make sure the vehicle is in park or safer yet have another person at the wheel. Turn the key to the run position and then briefly touch jumper to the positive battery post. If it turns over/starts, then your problem is that no voltage is being supplied to the wire at your starter solenoid when you turn the key. Get a wiring diagram and trace the starting circuit. Usually when you turn the key a voltage is generated when and if the park/neutral switch is functioning and in the right position. You could have an ignition switch/wiring problem, a park/neutral switch problem, or a wiring problem to your starter solenoid (assuming the starter checks out).

Logic says if it worked before work was done but doesn't now that something done during the servicing caused the problem. Check the wiring harness to the park/neutral switch, wiring to the starter, etc.

Good luck.