2021 BMW 3 Series G20 Fuse Box Diagram

The passenger-side fuse box of the G20 lives under the glove compartment, behind the footwell trim on the right of the car. Two quarter-turn fasteners hold the cover; fold it down and the carrier faces you with its connector towards the door. Model-year 2021 cars (built from July 2020) got a revised card: the July 2020 layout added fuses 27 and 47 and removed the 50 A fuse 41, and the November 2020 card printed for cars built from that month raised fuse 30 from 5 to 15 A and left position 35 empty.

The positions read top to bottom in every column. Upper left: the wide fuses 20 to 29 with the small fuse 30 under them; alongside from row 23, the small fuses 31 to 38; upper right, the three big fuses 39 to 41 above the relay. Lower left: 67 to 76 at the edge, 59 to 61 and 62 to 66 in the next column; lower right: 46 to 52 and, from the row of 72, 53 to 57.

The BDC fuses are the hardest to reach: the module sits at the right-hand A-pillar of a left-hand-drive car under the trim, next to the passenger footwell. BMW's card draws its six fuses between the connectors and rates them 5, 7.5, 7.5, 5, 20 and 20 A; the July and November 2020 cards for the 2021 cars did not change any of them.

The six sockets stand one above the other in the middle of the module, F1 at the top and F6 at the bottom, with CON5 and CON4 to their left and CON3 and CON2 to their right.

Behind the driver's footwell trim, on the left side of the car under the dashboard, is the smaller front power distribution box that BMW's workshop drawings call Z43. It carries the two terminal 30B relays R1 and R2 and thirty-one fuse sockets of which the 2021 cards populate five: 102, 107, 113, 117 and 118. From the July 2020 card onwards 107 dropped to 7.5 A and 108 was no longer fitted.

Unlike the other boxes this one numbers from the bottom right: 101 at the foot of the right column climbing to 104, 105 to 107 in the three small sockets above; then column by column leftwards, 108 to 113, 114 to 119, 120 to 125 and 126 to 131, always bottom up with the pair of small sockets on top. R2 is the left relay and R1 the right one.

Behind the trim on the right of the luggage compartment, the rear power distribution box is the G20's largest fuse carrier. For the 2021 model year BMW changed its card twice: the July 2020 layout turned spare slots 229 and 280 into a 40 A and a 5 A fuse and raised 296 to 30 A, and the November 2020 card printed for cars built from that month added 242, 251, 253 and 267. Cars built July to October 2020 therefore lack those four.

Every row counts left to right and every column downwards, seen with the big module top left. On the left: 200 to 205 and 206 to 211, then 212 to 216 alongside the wide 217 to 220, with 221 to 230 as the bottom row. In the middle: 231 to 240 across the top, the small blocks 242 to 246, 247 to 252, 253 to 258 and 259 to 264, and 265 to 274 across the bottom. On the right, part of the high-version box only: 276 to 280, 281 to 286 and the column 287 to 296.