My schematic shows the power feed to the fan fuse also powers the instrument lights.
Are these lights on? If yes, you may have a broken wire.
On Generation 1 (through 2007) KR650's, the 10-amp fan fuse does not protect instrument lights, according to this wiring diagram as I read it; rather, the fan fuse is in'line to the constant + 12 VDC line (WHITE) feeding the fan relay:
With a blown fan fuse on these models, only the fan should be disabled; all other electrics (including instrument lights) functioning. For testing, grounding the thermal fan switch lead (bottom of radiator) should activate the fan relay and turn on the fan on these models.
On Generation 2 KLR 650's (2008 and later models), the 15-amp fan fuse feeds switched + 12 VDC (BROWN) to the fan switch only, the fan switch when activated feeds + 12 VDC to the fan motor, the fan motor is permanently grounded [a different scheme from Generation 1 circuitry; Generation 1 fan switch feed a GROUND to the fan relay; Generation 2 fan switch feeds switched + 12 VDC to the fan motor]; similarly, loss of the fan fuse on these models means only, no fan; all other electrical circuits (including instrument lights) should be unaffected:
(I'll try to post an image of the '08-and-later wiring diagram):
Grounding the radiator fan switch manually on a Generation 2 KLR650 will not activate the fan motor; could blow the fan fuse. Shorting the two leads of the fan switch should turn on the fan.
Instrument lights should be powered by SWITCHED + 12 VDC, "upstream" of the fan circuit.
BRIEF NOTE: Very early KLR650's had no fan fuse; think it was added in the 1990's.
Back to basics, basement: What YEAR is your KLR650?
In summary; Generation 1 thermal fan switch provides ground, activating fan relay and consequently, fan.
Generation 2 thermal fan switch, when activated, provides full current + 12 VDC to fan motor (motor hard-wired ground).