Does your truck even have a "dinger"? Mine didn't, so I pulled one out of a parts truck. In the driver's footwell where accessory wiring and relays plug into there is a large (maybe 1" thick by 2 or 3 inches wide by 3 or 4 inches long) black module that plugs right into the accessory panel. It is a plug and play unit, the sound comes right from this dinger. Check that first.
Edit: My truck is a '98 and the donor was a '95, I don't know what years interchange as even the accessory box was a bit different between the two, but GM loves using the same parts on everything, so any year should work. Try your buddy's or your Dad's dinger before you assume it's the fuze