ive got an 89 w250 with no brake lights everything else works headlights, blinkers, and cab lights etc. but in the fuse box in the cab it says in slot #9 should be a 20 amp fuse for the brake lights, and door open alarm. but there is no slot #9 i am going crazy there are no fuses are blown, i have tail lights but no reverse lights or brake lights. what do i check next? i cant find a fuse box under the hood and it dosent say anything in the manual about another box?