Audio Systems: Light issues after I installed stereo

Question
I have a 1999 silverado z-71 I installed a ken wood stereo in. Stereo works fine but now when I turn off the truck my front  turn lights and tail lights will stay on and also the dinging tone stays on even after I take the key out of ignition. They all stay on for at least 5to10 mins then they'll turn off by themselves. It never did this until I put in the after market stereo.

Answer
DID you install a harness like this one ?
http://www.oemautosound.com/p-272-gm-radio-replacement-c2r-gm24.aspx

You cut the harness or you use only a cheap harness, i suggest you put the factory radio back in asap
or you are going to have a lot of problems with the vehicle BCM cluster and security system
you need the correct harness before you can remove the factory radio