2000 toyota tacoma prerunner turn signal problem. Both left and right flash when either is selected. Have replaced turn signal multi switch and flasher..did not help. What else should I look for?

It needs to be reset, here is how to do it:
turn the key on
set the odo/trip meter to read odopush and holsd the RESET switch
turn the key off while holding the switchturn the key back on
some lines will flash on the display
when the odometer reading comes back release the switch

if this doesn't work use the "trip A" setting instead of ODO
either one should work

check for a vacuum leak..

Replace the entire switch, not just the tumblers. Before installing the new switch take it to a locksmith along with your old switch key and have the new lock keyed to work with your old key. This will save you from having a different key for the doors & switch.

I have a 2002 toyota tacoma 2 wheel drive My key is stuck in the ignition and will not turn

some toyotas have seperate left and right headlight fuse. check the underhood fusebox

check the bulbs or the sockets for damage
or the wrong bulb
you are getting feedback through the wiring
and that lights up the dash

at the bottom of the dash on the drivers side,

turn your dimmer switch up it effects those lights and the dashboard

Usually this is a bit of dirt in the engine plugging the oil port that supplies pressure to the variable valve timing control cam. Change your engine oil every 3000 miles and maybe switch brands. I had this problem on my Matrix until I switched to Castrol GTX 5W30 that cleaned the oil port right out.

Try turning the parking brake handle and pressing it in. If that does not work then replace the under dash sensor on the parking brake (not the brake pedal). Hope this helps.