Nissan Repair: Reason for leak & overheating

Question
My son has a 1987 Nissan King Cab.  After driving with the air conditioner on, he noticed it was overheating, so he stopped using it.  Today, didn't use the AC and after driving for about 20 minutes, it overheated and coolant began to spew out.  He's really not sure what is going on.  There is rust in the reserve tank.  Does he just need to drain and clean both the radiator and reserve or could there be a bigger problem like the water pump, a head gasket, the heater core, or an actual hose issue?

Answer
Hi Stephanie -

Your overheating may be coming from your thermostat. If the car starts overheating after only about 10 - 20 minutes after you start it as you say, then replace your thermostat. I do not know what size engine you have, but it is probably at the outlet where the lower radiator hose connects to the engine.

LMK how this goes.

Hope this helps -
aloha
Calvin