2003 Toyota Tundra I Fuse Box Diagram

For 2003 Toyota fitted a larger engine box, still on the driver's side of the compartment but behind the battery, and OM34421U ("from Jan. '03 Prod.") prints it as plate R80020 for the 2UZ-FE V8. The model year's numbering reaches 44 across the truck, and most of it is in here. Unclip the cover: three cartridges over five blades and three blanks in the left column, the FL ALT link and a hatched second link socket in the centre, twelve blades standing on end in four groups of three numbered downwards, three more cartridges over blades 17 to 22 in the right column, and four relays across the bottom. The towing fuses TOW BRK, SUB BATT and TOW TAIL moved inside this box; HORN and OBD went the other way, into the cab.

Plate R80021 of the January 2003 manual is the 5VZ-FE version of the redesigned engine box, mounted behind the battery on the driver's side of the compartment, its lid popped off the clips. Three sockets are hatched on this drawing - TOW BRK and SUB BATT at 3 and 4, and the ST3 cartridge at 42 - and the throttle-control fuse sits in the V8's socket 18 as number 23, rated 15 A instead of 10 A. The rest follows the V8 plate: cartridges above blades on the left, the alternator link in the middle, the block of twelve blades on end, cartridges over blades 17 to 22 on the right.

Behind the trim at the driver's kick panel, left of the steering column; the cover pulls straight off. This is plate R80019, the familiar three-column carrier carrying the 2003 renumbering: 24 to 27, 28 to 32 and 33 to 36 read down the columns, the top-left socket empty, and the POWER cartridge above the right column as 43. Two circuits arrived here when the engine box was redesigned, OBD at 33 and HORN at 34, and the numbering runs across both carriers rather than restarting in either.