Hyundai Repair: 95 Excel electrical problem, printed circuit board, temperature gauge

Question
The temperature gauge in my 95 Excel moves quickly to the 3/4 mark however the engine is not overheating. When I activate the left turn indictor the gauge shifts to hot then moves in time with the indicator. When the indicator is switched off the gauge returns to the 3/4 position.
This only happens later in the day when the outside temperature is warmer. First thing in the morning it does not happen. Is it likely to be a problem with the wires or the gauge?  

Answer
Based on your description, it sounds like you have an issue (possibly a poor connection) in the ground circuit for the coolant gauge which is aggravated by the turn signal indicator.  This issue could be in the cluster's printed circuit board, the wiring, the ground lug, or in the I15 joint connector which is in the ground circuit.