1994 Dodge Spirit heater blowing cold but radiator is overheating

Couple of thoughts. are you losing water/antifreeze, do you have the right mixture 50/50 water/antifreeze. You did not say if the thermostat is removed or replaced. If thermostat is stuck closed water will no circulate. Are you getting any flow from the water pump. If your heater core is bypassed you should not get any hot air from the heater in the vehicle. Make sure your oil levels are good.
https://www.dummies.com/home-garden/car-repair/heating-cooling-system/how-to-troubleshoot-an-overheating-engine/
https://www.thoughtco.com/figure-out-why-your-car-is-overheating-281320

put a radiator flush in the expansion bottle .to clean the core of both your radiator and your heater. core will have dirt or rust .run the car for about 20 miles.then drain it .refill with 50/50 mix of anti freeze.now heating on full leave the cap off .turn over the engine,on tick over.push in the rubber hose with finger and thumb to remove the air out the bottle.then refit the cap.

For car running hot and overheating issues, I suggest to you go through this help links. Click this link below and go through the troubleshooting procedure to take care of the problems: ----Car runs hot? http://howtobyme.blogspot.com/2011/11/car-runs-hot-in-traffic.html
-----------All types of car overheating problems and troubleshooting?

http://technoanswers.blogspot.com/2011/11/all-types-of-car-overheating-problems.html
Car freeze overnight and started overheating while driving?http://technoanswers.blogspot.com/2012/01/car-freeze-overnight-and-started.html-----------Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Car overheats and Air blows hot at idle?
http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html
--------overheating? http://schematicsdiagram.blogspot.com/2011/12/buick-century-overheating.html
----------Car engine Overheats and transmission starts slipping?http://schematicsdiagram.blogspot.com/2011/12/car-engine-overheats-and-transmission.html
----------This details will help.Thanks.

For car running hot and overheating issues, I suggest to you go through this help links. Click this link below and go through the troubleshooting procedure to take care of the problems: ----

temp gauge goes erratic? http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html

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Temperature gauge keeps fluctuating up and down close to red? http://technoanswers.blogspot.com/2012/01/temperature-gauge-keeps-fluctuating-up.html

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Car runs hot? http://howtobyme.blogspot.com/2011/11/car-runs-hot-in-traffic.html
-----------All types of car overheating problems and troubleshooting?

http://technoanswers.blogspot.com/2011/11/all-types-of-car-overheating-problems.html
Car freeze overnight and started overheating while driving?http://technoanswers.blogspot.com/2012/01/car-freeze-overnight-and-started.html-----------Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Car overheats and Air blows hot at idle?
http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html
--------overheating? http://schematicsdiagram.blogspot.com/2011/12/buick-century-overheating.html
----------Car engine Overheats and transmission starts slipping?http://schematicsdiagram.blogspot.com/2011/12/car-engine-overheats-and-transmission.html
----------

Temperature gauge does not move and no heat when heater is ON? http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html

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This details will help.Thanks.

For car running hot and overheating issues, I suggest to you go through this help links. Click this link below and go through the troubleshooting procedure to take care of the problems: ----Car runs hot? http://howtobyme.blogspot.com/2011/11/car-runs-hot-in-traffic.html
-----------All types of car overheating problems and troubleshooting?

http://technoanswers.blogspot.com/2011/11/all-types-of-car-overheating-problems.html
Car freeze overnight and started overheating while driving?http://technoanswers.blogspot.com/2012/01/car-freeze-overnight-and-started.html-----------Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

---------------------------

Car overheats and Air blows hot at idle?
http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html
--------overheating? http://schematicsdiagram.blogspot.com/2011/12/buick-century-overheating.html
----------Car engine Overheats and transmission starts slipping?http://schematicsdiagram.blogspot.com/2011/12/car-engine-overheats-and-transmission.html
----------This details will help.Thanks.

To troubleshoot this types of problem,click the link below :---

All types of car overheating problems and troubleshooting? http://technoanswers.blogspot.com/2011/11/all-types-of-car-overheating-problems.html

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heater blows through defrost?

-http://howtobyme.blogspot.in/2012/02/heater-blows-only-from-defrost.html
--------Go through the procedure to confirm the issue.

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Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

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This will help.Thanks.

The heater is NOT actuated by a fuse, the fan is. ]But if the fan blows, the electrical part is OK, then it must be the heater door that switches from the cold air to the hot one, or 2) the heater core is not receiving enough hot coolant.

sounds like a bad heater core usually located under the dash and stereo

Replace the bad radiator hose first.  Second- get you special formulated anti-freeze dye from the auto store and pour it into the radiator.  Third- make sure you got all the air pockets out of your system, cause the coolant system won't work with air pockets in it.  Fourth- Check for leaks by looking for the colored dye.  If it's not the radiator hose, then could possibly be a pin hole in your radiator.  Would suggest replacing all the radiator hoses at the same time while you got the coolant system disconnected, cause you don't want to have to come back and replace another hose in a few months.

Be sure the system is full of coolant. what Engine is in it?