Fuse System
The fuse assembly is a component of the main harness. It is secured to an aperture provided on the bulkhead by integral plastic clips. The unit contains three operational fuses and has provision to house two spares. The fuses are protected by a pull-off transparent plastic cover on the bulkhead adjacent to the clutch master cylinder.
Failure of a particular fuse is indicated when all the circuits protected by it become inoperative. If a new fuse fails establish the cause and rectify the fault before fitting a second replacement.
| Fuse Manufacturer | Lucas |
| Rating | 35 amp. |
| Lucas Part No. | 188218 |
| Stanpart No. | 58465 |
Circuits:
The fuse fed by a white cable from the ignition/starter switch protects the following circuits:
Windscreen wiper, Stop lamp, Seat belt warning, Fuel indication, Reverse lamp, Temperature indication, Turn Signal, Heater
The fuse fed by a red/green cable from the master light switch protects the following circuits:
Front parking lamp, Rear marker lamp, Plate illumination lamp, Front marker lamp, Tail lamp, Instrument illumination
The fuse fed by a brown cable from the battery protects the following circuits:
Headlamp flasher, Courtesy light, Hazard warning, Key warning, Horn
-1975 Spitfire Owners Manual with updates from 1970 Mk3 manual
Fuse Ratings:
| Lucas Fuse Rating (British) | BUSS AGC Equivalent (American) |
| 50 | 30 |
| 35 | 25 |
| 30 | 20 |
| 25 | 15 |
| 20 | 10 |
| 10 | 7.5 |
| 5 | 3 |