Q: After change taillight and evaporation purge valve on 06 Cadillac SRX will not crank over or attempt to start key lock in ignitio

Well first off I change my rear tail light on my 2006 Cadillac SRX because you have to change the whole assembly it's been running fine besides the engine sounds a little rat Ali which I did some research and figured it was possibly the evaporation purge valve solenoid pick that up at the junkyard also with my tail light it ran before I changed it once I changed it I go to crank it it does not crank over the instrument panel does not come on the key is locked in the ignition the headlights work tail lights work the windows will not work radio does not work and it will not crank all I hear is a noise coming from I believe the ecm or computer underneath the engine bay where it's located also the instrument panel nothing lights up even with the headlights on only thing showing on the instrument panel is check engine light which is always been alone for the last few months

My car has 135000 miles.
My car has an automatic transmission.