Are your taillights bright, like brake lights? If so, it could be a malfunctioning brake light switch. If it's just the normal level light, I don't really know ... there's no combination on the stalk that should only turn on the rear lights.My tail lights will not turn off, however it's not the parking lights that is culprit ~ I tried it.
It is some configuration of fog light switch and headlights ~
Have you heard of this? Any ideas?