When I bought my 94 z28 with a convertible top the pump for the top was tested and working but the switch wasn't. Any ideas .ca He said when he messed with it he blew some 500$ electric piece.

 

"Car Audio & Electronics" isn't the best place for this question. I'll move it to a better forum for you.

 

Don't know if this will help or not, but hopefully it will. Here is a link to the Service Manual for your car. I have a 95 Z28 and looked up the info for Convertible in it, and the info for the wiring is in Section 8A-121-0 thru 8A-121-4 which includes schematics and troubleshooting.

https://www.mediafire.com/?40mfgeoe4ctti

On a 95 Z the #15 (Windows) in the fuse block is a 30 Amp Circuit Breaker that is for the Convertible Top

 

Not a lot of information to go off of. Does the radio work properly, including shutting off when the door opens after turning off the ignition switch? The reason I ask is because you mention the previous owner saying "he blew some 500$ electric piece". The Retained Accessary Power module contains a relay which supplies the voltage to fuse #7 and 15 (power windows, convert top pump, and radio) and GM Parts websites show the list price as around $500. If the rest of the RAP equipment is working correctly, check out the circuit breaker #15 to make sure it has continuity through it. I've attached a pdf with wiring diagrams to help guide you.