Where is the neutral safety switch located on a 2000 dodge caravan 3.3 liter engine?

If it has a 3 speed automatic, it's on the drivers side of the transmission front towards the engine.

Neutral safety switch may have broken.

No they are two different engines. Swapping them would involve changing over many other components besides just the engines. Including mounts, harnesses, computers, etc.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Are you saying the engine will not crank, or crank but will not start ?
None of the engine sensors come into play until after the engine is cranking.
Cranking problems can include the neutral safety switch and other factors with the crank circuit back to the key switch.

Safety Switch Most neutral safety switches are combinations of a neutral safety switch and a backup lamp switch. Others have separate units for these two distinct functions. When the reverse light switch is not part of the neutral safety switch, it seldom needs adjustment, as it is directly activated by the transmission or the gear selector linkage.
Typical location of a neutral safety switch on a transaxle. Reprinted with permission of Ford Motor Company. A neutral safety switch allows current to pass from the starter switch to the starter when the lever is placed in the P or N position. Some neutral safety switches are nonadjustable. If these prevent starting in the P or N position and the gear selector linkage is correctly adjusted, they should be replaced.
To adjust a typical neutral safety switch:

• Place the shift lever in neutral.
• Loosen the attaching bolts for the switch.
• Using the angling pin, move the switch until the pin falls into the hole in its rotor.
• Tighten the attaching bolts.
• Recheck the switch for continuity. If no voltage is present, replace the switch.
• The switch sometimes controls the operation of the back-up lights also. With the engine off and the key on, put the selector in reverse position. Check the back-up lights to see that they are on. Then, check in the drive position to see that they are out.

the neutral safety switch (Park/Neutral position switch) is located to the right of the transaxle range switch on the front of the transaxle, just above the fluid pan.

1. Disconnect the negative battery cable.
   
2. Safely raise and support the vehicle.
   
3. Disengage the electrical connector from the switch.
   
4. Unscrew the switch from the transaxle case.
   

To install:

1. Position a new seal washer, then screw the switch into the transaxle case.
   
2. Attach the electrical connector to the switch.
   
3. Lower the vehicle.
   
4. Connect the negative battery cable.
   

Are you saying that the shifter itself is not working correctly? Try putting the trans in neutral and see if the engine will start. If so, you may have a bad neutral safety switch.

If this does not help, or the shifter itself is not working smoothly, you possibly have a linkage issue.

Here is some info. https://dodgeforum.com/forum/dodge-caravan/231988-97-grand-se-3-3-prndl-neutral-switch.html

Transmission range sensor is what it is called .

It is in side the trans on top of the valve body. Why do you think you need to replace it?