tail lights not working but brake lights are Page 2

Your brake lights work but the tail lights don’t—classic “I’m visible only when stopping” trick.

Likely culprits, in order of how often they ruin weekends:

• Blown tail/park light fuse (separate from the brake light fuse).
• Dead tail light bulbs or dual-filament bulbs with the tail filament gone.
• Corroded sockets or dodgy earth/ground at the tail lamp cluster.
• Faulty headlight/park-light switch or relay.
• Aftermarket trailer plug or wiring tapping the park circuit and shorting.
• Broken wiring in the tailgate or behind trim.

Start with the easy wins: swap bulbs, check the fuse, clean contacts, and test for 12 V at the socket with parks on; if brakes power the brighter filament, wiring to the tail circuit is at fault.

If both sides are out, think fuse/switch; if one side, think bulb/socket/ground. When in doubt, a sparky can diagnose it faster than you can find the torch.