Try removing and re-installing the fuse labeled "SWM". This powers the Steering Wheel Module", which is the housing that has the headlight and turn signal switches. It's in the fuse box on the left end of the dash. This should reset the module. If that doesn't work, you'll need to take it to a shop that is very familiar with working on this vehicle, since it has a fairly complex computer network and diagnosing these types of problems can be difficult.