help needed on a 2004 Trialblazer!

i was told by the chevrolet place that there are magnets in the key switch which are used to make sure the only way to crank up the vehicle is with the correct key and they had gone bad. I'm almost positive they went bad because of splicing into the ignition wire. the reason i say this is that my retained power worked on the radio so i think after i switched the key off that first time there was still 12 volts running to the ingition switch for 15 minutes and the electricity probably messed up the magnetivity... that's just my guess on what caused the problem, but the magnets were the problem (yes, this is a passlock feature). i'll let ya'll know if i find out differently