Toyota Repair: 96 t 100 3.4, trailer wiring harnesses, lightswitch

Question
get into the truck no key in step on the brake. the brake lights come on along with parking lights. turn key on still the same when you hit the brake.but turn on lights no blinkers or flashers but turn off lights blinkers and flashers work. replaced all bulbs and combo switch(lightswitch and wiper switch assembly.  

Answer
There have been some problems with trailer wiring harnesses either factory or aftermarket, if this has a trailer towing hitch you may want to disconnect the elctrical portion completely from the rest of the electrical system and see if things work normally, if there is no trailer hitch wiring let me know.