Every time I turn the key to"on" the 20A GA./IDEL fuse pops? on 1990 Chevrolet 2500 Pickup

It started with the Speedometer not working and the Buzzer going off. Battery died and and wouldn't charge. tested Batt./Alt. Batt. was bad changed it. It seems I've stuck my meter just about everywhere. And every time I turn the key to just "ON" !POP!

Asked by for the 1990 Chevrolet 2500 Pickup
The only way to confirm what exactly is feed by the fuse that pops on your 1990 Chevrolet 2300 pickup is with a wiring diagram. The diagram I have shows a pink wire with a black stripe coming from what is called the "gauge" fuse. This circuit also feeds the "buzzer" and the low coolant module. I would begin by unplugging first the "buzzer" module and then the gauges cluster to see if the short goes away.