Its useful to look at the wiring diagram when sorting out your electrical problems.http://smokeriders.com/diagrams/Suzuki/Triples/Color_GT550.gif
If you didn't solidly connect something its not likely to blow the fuse unless the connector is so loose that its in contact with something that is causing the short. Otherwise a loose connector would just result in something like gauge lighting not working.
One possibility is that you moved the wires around a bit when working on gauge cluster and now a chafed wire is grounding to something.
A good starting point is to check some resistances with fuse removed and battery disconnected.
As others said, check the resistance between ground and the red wire leading away from the fuse to the ignition switch.
Do this test with:
1) key off
2) key on and lights off (if your bike has this option)
3) key on and lights on
4) key on, lights off and kill switch set to off (if your bike has this option)
5) key on, lights on and kill switch set to off
Rotate the front end to the left and right when doing these tests. Could have an intermittent short that is affected by this motion.
Check the wiring in the region you worked on. Does anything look blackened or burned by a short? Any repairs by you or a previous owner that could have gone bad?