Water pump maybe?
flush the system and change thermostat,this should fix problem. I flushed mine and i changed coolant and thermostat,it is now fine.
If it is leaking coolant. And you changed the thermostat. I would then move to this section. Flush the radiator and the heater core. This can be done at a certified shop with a reliable mechanic.
im having the same problem with my 1994 I've replaced the heater core,thermostat,radiator,i checked the coolant, and it's not over heating or nothing and still no heat lol
it is a hyndai that's why it is a hyndai that's why
Assuming repairs have been performed properly and there are no DTC's; you have an electrical problem.
Check that the coolant fans are still working, then check out the water pump.
It could either be your thermostat or your waterpump. In either case you could have full coolant levels but with a faulty thermostat or water pump your car will still over heat. I would start with the thermostat because those are usually the cheapest and easiest to fix.
Got coolant? Thermostat stuck closed? It could be the head gasket if you are very low on coolant and you cannot figure out where the coolant is going.
Coolant at proper level? System air bound and needs to be purged? Water pump not circulating coolant? Defective thermostat? Collapsed radiator hose?
Your thermostat has nothing to do with your coolant light. Your thermostat, if bad, would make your van run extremely hot, or not heat up at all. Your coolant light is probably a bad sending unit or ground.
Are both lines hot that go into and out of heater core? Plugged heater core will result in no heat, or other restriction.
your coolant level sensor is bad. change it.