Instructions
Determine if the capacitors are Radial or Axial. Radial capacitors have both the lead wires coming out of a single side. Axial capacitors have a lead wire extending out of both sides.
Examine the markings on the capacitor casing. An arrow pointing toward the negative lead wire may be stamped on both Radial and Axial capacitors. Additionally, the negative lead wire of a Radial capacitor may be indicated with a black stripe.
Look at the sides of the capacitors. The positive side may be composed of black rubber while the negative side may be made up of silver aluminum.
Compare the lengths of the lead wires. The socket with the shorter lead wire is the negative side.