1994 chevy caprice no heat. changed termostat. antifreeze full. fans in back of radiator are not moving

Use a garden hose and flush your cooling system (specifically the heater core) to clear out any blockage or buildup. Once the water comes out clear put the hoses back on and refill the radiator and overflow tank with 50/50 Antifreeze and see if you have heat. If not the next thing to check/replace is the heater core itself.

Turn off the ignition of car.
Let the engine and radiator cool.
Refill the coolant to the required quantity with the approved type.
Wait until the coolant helps reduce the heat completely.
You should not see the light now.

i beleve your thermostat stuck open

you have air in the system ,if you have not done a radiator clean ,the put radiator flush in the radiator then go for a short run.about 5 miles then go back and drain the radiator.now remove both radiator hoses.fill with water it will pour out as you do so..if clear refit you hoses.fill will a 50/50 mix of antifreeze. now put your heating on full open your window .with your expansion bottle cap off ,run your engine on tick over till the water starts to head up.then refit the cap.this is done to bleed the air out both in your heater core .and the radiator.

Well, it all depends...

One is called an "A/C Condensor Fan". This one comes on whenever the air conditioner is running. The other one is the radiator cooling fan. This one comes on when the engine temperature reaches a certain point and the engine computer commands it to come on.

If either of these fans fail to work at all, the circuits must be diagnosed to locate the problem. It could be a bad fan motor, a bad fan control relay, a malfunctioning engine coolant temperature (ECT) sensor, or broken wires or loose connections between any of the components.
Low engine coolant (antifreeze) can even keep a radiator cooling fan from working (the ECT will not work correctly if the engine coolant is low).

first of all your car shouldnot be overheating. if itis, check your antifreeze level in your radiator, for a leak, hose, water pump etc. termostat. And yes both fans should be on, that is controled by the pcm.For that is used a temperature sensor. and if the fan it never turns on check the fan and relay. electrical conection too. hope this will help you.

take off the radiator cap and fill the rad with antifreeze. start the montor and keep watching the level of the antifreeze and keep adding as necessary. when the termostat opens you sould shee a sudden drop in level.... keep adding antifreeze. squeezing the upper rad hose will help remove air bubbles. BE EXTREMELY CARE OF THE FAN AND OTHER MOVING PARTS TO PREVENT INJURY. after you are satisfied that you have added enough fluid put the rad cap back on. fill the overflow tank to the leven it indicates.... take it for a drive and let it cool down. open the rad cap and top of the fluid if necessay.

The heat is made in the engine so if the engine is overheated and nothing else is hot, the water is not moving.
I would have suspected a thermostat also.
I would guess now that you have a dead water pump.

Karl at topgunwon.com

Check your fuse and relay to the radiator fan, There going to be high amp fuse so most likely will be in the fuse box by the battery. If the fuse and relay is good, check the wire harness connection at the fans. The other thing to is to run the engine and turn on your A/C, the A/C should over ride the switch and turn on the fans. If the fans do turn on, inspect the radiator fluid, make sure it's at it's level and if it's never been serviced. It may be time, Orange antifreeze has a life of 150,000 miles or 5 years and the green antifreeze has a life of 30,000 miles and 1 year. The thermostat may also gone bad but i don't think at this case since your car only heats up while your stopped. If everything is working (fan) just replace the antifreeze 50/50 mix (Antifreeze/water), Water has great heat transfer but boils so antifreeze is added, and 100% antifreeze does not have great heat transfer and will gel when heated so the two have to be mixed 50/50 and if your not sure how to mix the two. You can buy them 50/50 mix and the capacity to your car total fill is 7.3 liter 4 cylinder/ 8.6 liter 6 cylinder. 

Make sure you have 50/50 mix antifreeze, it will still run hot if you have 100% antifreeze. As the antifreeze get's hot, it turns in to gel and the flow slows down and the heat exchange will be reduced. Water is great in transferring heat but it will boil over so antifreeze is added to keep it from boiling over, so a 50/50 (water/antifreeze) mix is used. You can go a bit higher with the antifreeze but try not too and in the winter you can go 40/60 (water/antifreeze) if your in really cold climate area. The other thing to is do you have electric radiator fans?? Think you do, make sure it's working. When you turn on your A/C the radiator fan should come one and also when the temperature  gauge hits 180 - 195 degrees the fan should come on too. If not check the fuse, relay's and wire harness to the fan. Good luck and hope this helps.