Volt/OHM meter can be your best friend
Put the black meter probe on a good Ground to metal for these tests
Any Fuse has 2 contacts(slots), the Volt slot and the Load slot
Pull out the fuse and use the volt meter to test which "slot" has the 12volts, if neither is 12v then turn on the key to see if this is a Key On fuse
Once you KNOW which slot is 12v then the other slot will be the Load slot, the one with the SHORT, if fuse was blowing
Switch meter to OHMs, 200 ohms, if that selection is available
(If this was a Key on fuse then you can turn off the key now, if you want, so battery is not draining)
Put Red meter probe on Load slot, if there is a short to ground then you should see under 10 ohms, 0 ohms is a direct(dead) short
Start unplugging connectors to see if ohms go UP, short was removed
Note on Meters and OHMs, when ohms is selected you may see an N/C in display, this means No Connection, touch the two probe tips together and you should see 0 ohms, direct connection
Some meters show a "1" when ohms is selected, touch the two probes together and that should change to 0, the "1" doesn't mean 1 ohm, its just a symbol meaning ohms was selected
Most Volt meters also have a Continuity test setting, has a Diode symbol, like this --<|--, a triangle
Select that setting, then touch the two probe tips together, you should hear a tone from the meter meaning there is no resistance(ohms) between the two probes, tips are shorted together
You can use this setting on the Load slot and Ground, and should get a tone from meter if there is a short in this circuit, so you can Hear if the short is removed by moving wires around(short inside harness) or unplugging connectors
This testing saves on fuses, and even circuit breaker fuses do have their limits, they will fail if they are "blown" too many times