On my 1990 4runner, when my lights are OFF, hitting the brakes turns on the tail lights, when lights are ON, the brake lights are always ON and hitting the brakes changes nothing, I can't find anything obvious, all the bulbs are good etc. It just started out of the blue one day...

You need to check if you have a splitter for trailer wiring installed, if not, you have a short. If you have one remove it completly and ck scotch lock connections.

Sure sounds like the bulbs are in backwards................

How do you put the bulbs in backwards? By the way the problem with the taillights was nearly two years ago, I'm sure it's no longer a problem.

How do you put the bulbs in backwards?

With a bit of force...