My 2000 neon blows heat but it wont get verry hot i replacer the radiator and the thermostat and still not much heat

So the blend door opens? Does the fan motor blow? Are both heater hoses hot? That would indicate the coolant is circulating through the core.

1) The "heat" cycle on a vehicle depends on the engine's operating temperature when "heat'' desired," as well as the "external temperature of the atmosphere; colder days will create "lower" internal temperatures for the vehicle's passenger compartment as related to the amount of cooling of the radiator fluid through the radiator.
2) One option exists as to place "a 'piece of cardboard' in front of the radiator itself," especially in very cold areas of the country.
3) The other problem may involve your "thermostat" of the vehicle being "bad" (they fall apart sometimes), versus being of the wrong temperature variety; In this case your "automotive technician" should be consulted so as to replace your vehicle's thermostat with a different thermostat.
4) Lower temperature thermostats (185 F) open the system to the engine at 185 degrees; with 195 F opening the system at 195 degrees.
5) One of these solutions (the cheapest being the cardboard) may be of assistance (just remember to remove the cardboard in the summer/spring).
6) As of 03-09, 2019 @ 1448 CST; I'd like to add this comment to my above earlier data: It's "best" to never "change" the thermostat rating (exampled from a 185 to a 195; even vice versa) on your vehicle. Simply use the cardboard, removing it with warmer weather.

thermostat is sticking open

try flushing or replacing the heater core for some reason they get clogged

REPLACE THERMOSTAT.MAKE SURE COOLANT SUPPLY PIPE OR COOLANT RETURN PIPE NOT STOPPED UP AND YOU HAVE ENOUGH COOLANT IN THE SYSTEM.REPLACE THERMOSTAT.CRANK ENGINE UP AND LET IDLE UNTIL WARM UP KEEP EYES ON TEMPERATURE GAUGE. WHEN ENGINE THERMOSTAT OPEN COOLANT HOSE SHOULD BE HOT.IF NOT TURN OFF ENGINE.USE LARGE RAG WAIT A WHILE BEFORE REMOVING RADIATOR CAP CHECK TO SEE IF COOLANT LEVEL DROPPING IF SO ADD MORE COOLANT.CRANK ENGINE UP UNTIL THERMOSTAT OPENS UP.HOSE WILL GET HOT.IF STILL COLD CHECK COOLANT LEVEL.ONCE YOU AIR OUT COOLANT SYSTEM RADIATOR HOSES WILL GET HOT SO YOU WILL GET HEAT.IF COOLANT LOW YOU WONT GET NO HEAT.

yes if its not full of coolant it wont blow heat... let it cool down, fill it with coolant, start the vehicle with your defroster on, all the way over to hot, and on high, watch the level of the coolant, when the thermostat opens, the coolant will be sucked out of the radiator, top it off, after a few minutes you will feel heat.

you need to replace the thermostat.... quick fix for now is to put a peice of cardboard or similar in front of the radiator to stop airflow.

Robert

If rad/cooling system runs low on coolant, it will starve heater core of hot coolant that it needs to put out heat. Fill rad, with heater on, and cap off, to bleed out any air in system while you run it for a while with cap off, and see if that doesn't give you heat back.

Did you make sure all the air was bleed from the cooling system? to do this jack the car up in the front with a floor jack as high as poss, then fill the coolant recovery tank up, run the engine until it is hot but not overheated, shut the engine down and let it cool, this should purge the air from the system, if the system checks ok then but later starts to act up again the the problem is a leaking head gasket. One last note make sure the recovery tank is refilled, it will **** down.

Sounds exactly like what my mom's car was doing as for the blower only working on high. It was the resistor... I assumed it was the climate controls and replaced them but it didn't change anything then i thought that i must be the blower motor and replaced that too but it turned out to be the resistor which is under the dash on the passenger side of the car.