Part and system guide

Fuses and Relays

Fuses protect circuits from excessive current, while relays switch higher-current loads using control signals.

What it does

Help power systems such as the starter, fuel pump, cooling fan, lights, and HVAC circuits.

Failure signs

  • No sound when starting
  • Fuel pump silent
  • Radiator fan not running
  • Power window failure
  • Intermittent electrical operation

Maintenance notes

  • Replace blown fuses only with the correct rating.
  • If a fuse blows again, find the short instead of installing a larger fuse.
  • Swap relays only when part numbers and circuit roles are appropriate.