Truck door chime 1990 Chevy c1500 4.3?

I have a 1990 Chevy c1500 4.3 and I have no door/light chime for if I leave my keys in the truck or if I leave my lights on. I want to install a chime on it I want to get the new ford f150 chimes how would I get that chime. Could I go to the junk yard. If so how do I unhook it to hook it up o my truck. 1 more thing I'm hooking up electric fans in my truck and I need to find and ignition wire for them I'm not cure where the ignition wire iscoukd I hook it up to my starter wire or could I hook it up to my alternator wire. Thank you. Or if anyone knows a better place I can hook it up to would be great this is the door chime I want my fan kit is a derale 16720

There's a buzzer that should come on when the key is in and the engine is off or the engine is running and the door is opened. The key in switch has 2 white wires going to it. Open your steering cowl and you might find the connector is not connected.