Should you use a 13amp in your plug or a 3amp for a side light?

For a side light, you should use a 3-amp fuse rather than a 13-amp fuse. Side lights typically have lower power requirements, and a 3-amp fuse provides adequate protection without being overly large for the application's needs. Using a 13-amp fuse could pose a safety risk, as it may not blow in the event of a fault, allowing excessive current to flow. Always ensure that the fuse matches the specifications of the light fixture.