97 dodge cooling fans stoped working

There are two possibilities, one is the thermostat. Many people remove them which spoils the whole heating / cooling system. Since you changed the thermostat, I would check the heater valve on the heater which allows the hot water to circulate through the heating system.
It may be necessary to remove the heater box and flush the heater core since you talk about a lot of rust, which could have clogged the heater core and / or the pipes leading to the heater.

Hi, Sounds like you need a radiator flush. If the radiator is plugged up it can not cool the engine properly. Have it cleaned out and it should work fine. Good luck.

Yes, it could be a few issues, I always believe to go the cheapest route first, so you are not just replacing parts to be replacing, Based on your description, Normally it would not be overflowing if your pump is not working, It could be a clogged hose, you would have to flush system to see if that was the case, but based on my feeling, i believe it is a stuck thermostat, If your tank is overflowing, it would have to be a main hose block, but i don't believe that is the case, i would have thermostat replaced, to confirm that, for a around 50 bucks (if you stay away from dealer) you can have the radiator flushed, which is a good idea anyway, then you will know for sure it is the thermostat, and they can put that in after they flush it, or you can put thermostat in, pick there brain, when they flush it, and they can point where it is, it is just a couple of bolts to take off, clean gasket area, replace with new gasket, after of course taking old thermostat out and replacing with new one.

I hope this helps you, (again, i think it is thermostat that is stuck) thanks Mike from fixya

Couple of other items to check: A) radiator cap - it might be weak and not holding pressure B) thermostat in upside down - (not implying but it does happen) C) blown head gasket D) Fan belt slipping past waterpump - glazed
It sounds like you did everything, just back track over everything

What engine? i'll assume it's a v-6 is the radiator/coolant level proper? is the belt on the water pump? when it's running or idling before it overheats or as it's getting hot does the engine cooling fans come on? if you stand in front of the van at grille you will hear fans start up and run as it gets to >215*f or you should. if you don't it probably is the fan relay as these are common to go bad. it's a little electrical assy. located on the left side of the radiator shroud/support area best reached from underneath. they are not cheap and they are kind of hard to see and get to. if all the above is working your thermostat could be stuck shut and you'll need a flush and thermostat change.

IF COOLING FAN STAYS ON WHILE CAR IDLING AND DONT TURN OFF YOUR ENGINE IS RUNNING A LITTLE HOT.YOU COULD PARTIALLY CLOGGED RADIATOR OR ENGINE BLOCK PARTIALLY STOPPED UP ALSO THE THERMOSTAT NOT OPEN ALL THE WAY.HAVE VECHICLE SCANNED TO SEE WHAT COOLANT TEMPERATURE IS IF HOT.HAVE RADIATOR SHOP PRESSURE TEST COOLANT SYSTEM AND FLUSH OUT RADIATOR AND ENGINE BLOCK CHANGE THERMOSTAT.

Change your thermostat before it sticks closed completely. Sticky thermostat is usually the cause.
Another possibility is that your radiator fan temperature switch is going bad. This is usually located next to the upper radiator hose at the gooseneck on your engine where the thermostat is located.

sounds like you need a new heater core

Have someone flush cooling system & check condition of rad for debris in front of rad & blow or spray it out as necessary. Next time it runs hot, turn your heater temperature up high, blower fan on high, and see if gauge starts to come back down a little. If it does, my guess is your rad needs replacing, or at least consider trying a good reverse flushing of the system first, then rad.

i have a 97 dodge caravan sport had same problem and it was a fan relay.