I recently picked up a naked 1985 K100 with only 13,000 miles.

When I flip the rocker switch for the heated hand grips the battery light comes on and I lose the idiot lights on the gauge panel.

I found that the 7.5 fuse is blown. Replaced it and tried again same result.

Upon replacing the fuse everything runs fine until i play with the heated grips rocker switch.

I am probably going to just take the heated grips off line.

Has anyone had a similar problem / fix ?

Don

Could be an earth short between the switch and heater or a dead short on one of the heaters. Test the impedance on both.
Which fuse is blowing?

The top fuse on the panel ( a 7.5 ) blows when I toggle the heated grip switch.

That's the correct fuse so its probably connected in properly.
Find the connector under the tank/left side and measure impedance across the pins. Should be about 9 ohms. If no or little resistance then you got a dead short.
Measure from each pin to earth. Resistance should read infinity. if not you got an earth short.

More than likely a dud heater element (dead short)

I lifted the tank up today and found the heated grips plug. Unplugged it for now. Problem solved until winter time when I'll tests the heating elements.

Thanks all for the help.