Personally I wouldn't use a fusible link inside the car. These work by burning themselves open. If the link is next to other wires, it burns those too. If you want to fuse it use an in-line fuse holder. My opinion is that a fuse in the tach line is there to protect the dash wiring, not the tach. If the aftermarket tach develops a problem and blows the fuse, chances are the tach has a problem. It's going to be cheaper to replace the tach than to get it fixed. Try 5 amps.
A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!