Chevrolet Repair: 2003 monte carlo ss, monte carlo ss, gm tech

Question
my son has a 2003 monte carlo ss 3.8l
would not start 1 nite turn the key nothing no power to starter so i replace the ing. switch  and started right up i did not have try to start it and wait 10min. for secrutiy lite to go off i started right up  but my problem now is he has no cruise control or heater  i think maybe the bcm is bad now i have no bcm code
any ideal what it may be
fuses all ok  and no power to heater vswitches
need help thanks
bob

Answer
HI BOB,THIS DOES SOUND LIKE A POSSIBLE REFLASH PROBLEM WITH BCM. THE OTHER POSSIBLE CAUSE IS MAYBE A SPIKE TO THE BCM.  DID YOU REMOVE BATTERY POST BEFORE REPLACING THIS SWITCH ??? SOUNDS LIKE YOU ARE GOING TO HAVE TO MAKE A TRIP TO THE DEALER OR SOME SHOP THAT HAS THE GM TECH SCAN TOOL TO CK THIS. SORRY I COULD NOT HELP YOU MORE WITH THIS..GOOD LUCK TOM..