Cadillac Repair: 1991 Cadillac Brougham audible tone, 1991 cadillac brougham, cadillac brougham

Question
I have a 1991 Brougham that is providing a steady tone (alarm) when the vehicle is put into reverse and drive only. Nothing has been altered in the way of the electrical system, same as the day it was purchased. I am sure of this as my grandmother purchased the car new. It has just turned 100,000 miles and I have noticed the spring return on the switch located in the driver's side door jam is not returning and the interior lights do not work with this door opening. The lights work fine when using the other doors. Is that switch indicating the door to be open when the car is put into gear causing the alarm?  

Answer
Hello,

You door jamb pin switch is defective and is no big deal to change. Get one from the dealer and install yourself. All youneedis a 7/16 box wrench or deep well socket. Unscrew counter clock wise. Once removed you will see some pigtail connectors attached to the back of the switch. Reattach to new switch and screw in until tight.

Now, your buzzing problem may just be a bad tone generator mounted to the fuse box under the driver's side of the dash.

I would replace the pin switch first and see if you still have the buzzing. One shouldn't relate with the other, but replace the bad pin first and get back to me.