Vehicle thinks the key is in the ignition

[tim1]

Okay starting a new post after much searching. My 93 thinks that the key is in the ignition and that is what killed my battery. When you open the door the interior lights come on and a chime comes on, the chime comes on without the key in the ignition just from opening the door. I spoke with a GM Vet guy and he states the chime only comes on for three reasons, the lights are on, the seatbelts are not fastened or the key is in the ignition. He stated that there is a small plastic piece that fails, believe he called it the KEY PRESENCE SWITCH. I am suppose to get the ignition switch replaced this week so I thought I might as well have them replace that also.
Does this sound like a possible cause for the chime to come on when the door is opened?
Anyone know were I might be able to aquire a key presence switch?
Thanks for looking

 

[DaveP85C4]

There is a simple test to verify that the "key in ignition" switch is the culprit: With the key out of the ignition, one door open, lock the doors with the power locks. Open a window so you don't lock the keys in it. Close the door. The BCM unlocks the locks when a door closes with the key in the ignition. The locks should have unlocked when the door closed if the BCM still "sees" the key in the ignition.