1996 Dodge Dakota heater core

See pics for removal the whole heater unit h as to be removed then split and replace core.

This is an involved process. Here are the directions for a dakota without AC. If you have AC, let me know.

1. Disconnect the negative battery cable. Drain the coolant.
2. Remove the steering column cover, intermittent wiper control, if equipped and the lower instrument panel module retaining screw to the right of the steering column.
3. Remove the center distribution duct retaining screws and panel support screw at the bottom of the module.
4. Remove the courtesy lamp at the lower right corner of the module and the screw near the ash receiver.
5. Open the glovebox and remove the screws along the top edge.
6. Move the module out and down far enough to unclip the wiring harness and antenna cable and disconnect the speaker wire (if equipped with monaural radio) and glovebox light wire. Remove the module from the vehicle.
7. Remove the center air distribution duct.
8. Remove the antenna wire from retaining clip at the right end of the heater unit.
9. Disconnect the blower motor connector and remove the thermal insulator retainer from the heater unit.
10. Disconnect the demister hoses from the adaptor at the top of the heater unit.
11. Disconnect the vacuum feed line from the check valve.
12. Disconnect the temperature control cable flag retainer from the heater unit.
13. Remove the adjusting clip from the blend air door crank.
14. Disconnect the heater hoses from the core tubes and plug them.
15. Remove the four heater unit attaching nuts from the rear engine compartment dash panel.
16. Remove the heater unit support attaching screw and rotate the brace out of the way.
17. Remove the heater unit from the vehicle.
18. To disassemble the housing assembly, vacuum diaphragm and retaining screws from the cover and remove the cover.
19. Remove the retaining screw from the heater core and remove the core from the housing assembly.

To install:

20. Remove the temperature control door from the unit and clean the unit out with solvent. Lubricate the lower pivot rod and its well and install. Wrap the heater core with foam tape and place it in position. Secure it with its screw.
21. Assemble the unit, making sure all vacuum tubing is properly routed.
22. Install the assembly to the vehicle and connect the vacuum harness. Install the nuts to the firewall. Install the support brace to the heater unit.
23. Connect the demister hoses to the adaptor at the top of the heater unit.
24. Connect the blower motor connector and install the thermal insulator retainer to the heater unit.
25. Connect the vacuum feed line to the check valve.
26. Connect the temperature control cable flag retainer to the heater unit and install the adjusting clip from the blend air door crank.
27. Install the center air distribution duct.
28. Install the antenna wire from retaining clip at the right end of the heater unit.
29. Install the instrument panel module and all related parts.
30. Connect the heater hoses to the core tubes.
31. Fill the cooling system.
32. Connect the negative battery cable and check the heater for proper operation and leakage.

Replace the thermostat. 175 degrees is way too cold. If you check the diagnostic fault codes, you'll see you have one set for "engine running cold too long", meaning it's not up to operating temperature within six minutes of starting.

Now that neither one works, check fuses. Also, check body ground straps in the area you worked. Chances are you have a bad ground.

Sounds like the system needs to be bled of air, there is probably an air bubble trapped causing coolant not to flow properly.

Yes, that sounds like the issue to me.
That is correct, you will have to flush the coolant system.
The heater core is inside the dash, it is a rather long repair job.

To better assist you, I would need the 8th letter of your VIN number.
Is this the 5.9L or 5.2L engine?

NO HEAT

Check heater core hoses if both are hot, if not the heater core need to be flushed as a 1st step
these are the steps
WARNING: NEVER REMOVE THE PRESSURE RELIEF CAP UNDER ANY CONDITIONS WHILE THE ENGINE IS OPERATING. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN DAMAGE TO THE COOLING SYSTEM OR ENGINE AND/OR PERSONAL INJURY. TO AVOID HAVING SCALDING HOT COOLANT OR STEAM BLOW OUT OF THE COOLING SYSTEM OR DEGAS BOTTLE, USE EXTREME CARE WHEN REMOVING THE PRESSURE RELIEF CAP FROM A HOT COOLING SYSTEM OR DEGAS BOTTLE. WAIT UNTIL THE ENGINE HAS COOLED, THEN WRAP A THICK CLOTH AROUND THE PRESSURE RELIEF CAP AND TURN IT SLOWLY UNTIL PRESSURE BEGINS TO RELEASE. STEP BACK WHILE THE PRESSURE IS RELEASED FROM THE COOLING SYSTEM. WHEN CERTAIN ALL PRESSURE HAS BEEN RELEASED, PRESS DOWN ON THE PRESSURE CAP (STILL WITH A CLOTH), TURN AND REMOVE PRESSURE RELIEF CAP.
Engine cool
lower the coolant level
Locate the two hoses running to the heater core
disconnect them at the engine side leaving hoses connected to heater core throw the firewall
use garden water hose and compressed air if possible
run the water and follow by air throw one side and out the other and vice versa
do that two to three times watching what leaving the heater core you are looking for the good flow and clear water to run throw
reconnect hoses
top off coolant system
good luck
let me know