rubber ducky

Ok, got a 98 grand cherokee - When I start my jeep both headlights come on. When I release the key the passenger side light typically goes out (sometimes it may stay on like the drivers side - about 80% of the time it will stay out)....This has been going on for about a month. Now it looks like my drivers side turn signal works intermittently as well. About to take jeep to mechanic in 3 weeks so hopefully I can get this sorted out myself. Also, onboard systems tells me coolant sensor is bad. I see two sensors (one on the top rad hose and the other on the bottom rad hose). Which sensor is the coolant one? Is there a way to test the coolant sensor to verify it has failed?

Any help would be great !!!