Overheating issue

The engine coolant temp. sensor is located on or next to the thermostat housing, except for the 3.0L engine..in that case it is near the distributor.

if you are talking about the cooling fan relay, it is at the front of the left frame rail, picture below

Not a bad idea to have the thermostat replaced
although I would do a pressure test on the system checking for leak
as it may be a water pump
and or hose and so on

Usually when this happens, its because the item it is controlling is going bad and pulling too many amps.

Check thermostat
check fuses
and if all ok suspect fan relay module
located Front of left frame rail

good luck

Start with a cold van. Disconnect battery negative cable.
Dump yhe coolant by pulling off the lower hose at the bottom of the radiator or at the water pump side if applicable. Now remove the upper hose.
I take the upper shroud, fans, and wiring off the radiator as an assembly. The hard part is getting to the lower shroud bolts, all four are 10 mm. Sometimes clips are used so they must come off with a screwdriver or pliers. Then I take off the two hold downs on each side on the top. Now with the fans and shroud out of the way, free up the condenser screws so it stays.
Some attachments on the bottom of the radiator may be removed if necessary. Now the transmission cooler lines and overflow line comes off. Lift it out slightly for more room to get at them.
Whether you use the drain valve or lower hose to drain it expect a mess. That's why I use a large drain pan and take off the lower hose.
If replacing be careful to swap the various fittings to the new radiator.
Reverse to replace. Use safety glasses. Put a gallon in and hook up battery and start it up. Wait for the thermostat to open and top it off and close the cap. Check the overflow container and bring it up to the hot level. You'll know when the thermostat opens when the level in the radiator drops and smoke and heat enters the radiator. So removing your drain bucket should be your last step. Hope it helps you. I haven't done an easy gravy job like that in 20 years but there all alike since 96 when CAD design made the Caravan look like a Ford.

To pressure test and give you an estimate, most repair shops will charge an hours labor and if you decide to fix it there it is usually included in that price, depending how serious the fix is.

The next time that it overheat, verify that the radiator fans are working. Your fans may not work, or your thermostat is sticking closed.

My van is overheating. We have checked all the fuses, replaced the sensor and relay switch. And the fans don't run?

Its gonna be overheating bcuz the cooling fan is not turning on-You can try this apply battery voltage to the fan motor and see if it comes on -let me know we stiil got other areas to look at-