Recent problem with my 2000 cherokee sport I know you see this problem a lot but mine has me stumped read entire thread before telling me to do the usual plug and play repair. With headlights on my brake lights are all on (all 3 in back ) without me applying brakes. With headlights off when I hit brakes marker lights come on with them. So first I check and change bulbs all bulbs even marker light bulbs inspect and clean the sockets etc...it continues to do it.. next I remove headlight switch and apply brakes and markers still come on I replace headlight switch anyway because I was already there..still does it ...next I remove stop light switch turn on headlights all 3 brake lights still come on I replace brake light switch for good measure but it still does it...I read some things online about possibly being the hazard switch so I replace that all fuses and relays etc and it still does it..so then I'm like "challenge accepted" I start getting tricky on this thing I pop hood I pull fuse #19 (parking light fuse) on the fuse panel under the hood hit brakes parking lights still come on without that fuse in there.. so I put it back in I go to fuse panel inside truck #7 fuse (driver side marker fuse) and #23(passenger side) I pull em both I hit brakes and now only passenger markers cone on without the fuse even in there...how is this possible? I definitely have it down to a passenger side problem but can't finger if its a marker light problem or a brake light problem. It even does it without the bulbs even in there or fuses out etc. What I'm assuming is somehow the brake light is over drawing power then overflowing it back to the marker light but I could be way wrong and it could be something crossed with the marker light idk ...but what could cause it if I am correct?