As always, first thing to check when any crazy electrical mess begins (especially with the cluster) are the grounds within the engine bay (typically drivers side)
As for overheating - test your thermostat/ once warmed up do both radiator hoses become hot?
when was the last time the water pump was changed?
if you run the heat on full blast at your feet, does the temp go down?
any milky residue beneath the oil cap/ any coolant in the oil?
smell coolant at all within the bay?
stupid question - is the radiator full?
Also, if any of those tests/checks don't help you resolve your overheating issue, you could try this. You may need to bleed the system of air. Assuming the radiator is full, see if you can find a funnel to snugly fit into the opening of the radiator. Sometimes a (clean) soda bottle cut in half, with electrical tape wrapped around the cap opening will fit snugly. Fill it with coolant just above the opening of the radiator.
Then just leave the car running at idle with the heat fully blasting inside. You can even have the front of the car at an incline, to ensure the radiator cap is the highest point, to help air escape out of system. As its idling squeeze the radiator hoses a bit too, to see if maybe you can release any trapped air. I would leave it for 15-20 minutes but just keep an eye on the temp gauge and make sure the engine fan turns on.