Have a 1999 T&C. Recently had the turn signal unit replaced at Chrysler dealer. The right turn signal had not been working. Acted like a bulb, rear, but was not. They replaced this unit and for about 4 or 5 days the signal worked. Turned into a driveway and its topped working. They are going to replace the unit, again. They also mentioned may have a short from the trailer light harnes. We've had the vehicle since 2003 andf ahve never used tralier so have never exposed it to elements as far as I know. Is a short easily determined?