Unless there is only one gauge , I don't think they are generally fused separately, but all gauges through one fuse off the ign. terminal of the switch . So it's hard to say what you had.
This Faria/Suzuki fuel gauge installation guide doesn't mention the fuse requirement-
http://www.faria-instruments.com/sit...fuel_gauge.pdf .
Probably 1 amp would be way plenty for 1 gauge on 18 ga cable , but just guessing there.
That wasn't the bulb by any chance was it?