Re-attaching hose to coolant reservior in 1996 Plymouth Neon

Nothing.
The second hose is the actual overflow hose where coolant escapes should the tank become full.

Well if your coolant reservoir is leaking and its not a hose thats cracked or leaking you have two choices:

1.Buy a new reservoir and install (highly recommended).

2.try to patch it with something that will bond to plastic and doesn't melt.(will probaley cost more then a new reservoir if you go out and buy it)

best bet buy a new one, or if low on funds call auto junk yard for used one.

They are tough, all the way back under the engine opening-I use a clear hose attached to a funnel-the hose end goes into the reservior, the funnel end into the other, outside the enclosed area-pour into the funnel, with the hose in the tank, it is a pain, pour slowly.

TO CHANGE RADIATOR FIRST YOU TURN OFF RADIO FIRST TO KEEP FROM LOSING RADIO CODE.DISCONNECT NEGATIVE BATTERY CABLE.RAISE FRONT OF VECHICLE SUPPORT ON JACK STANDS.REMOVE THE LOWER SPLASH SHIELDS.NOW YOU NEED TO DRAIN THE COOLING SYSTEM.CATCH COOLANT IN A LARGE DRAIN PAN.REUSE COOLANT IF ITS FAIRLY NEW.IF COOLANT VERY OLD CHANGE IT.PUT OLD COOLANT IN SOME EMPTY CONTAINER TAKE TO A GARAGE OR WHOEVER DISPOSE IT.DONT POUR ON GROUND.HARMFUL TO THE ENVIRONMENT.MOVE THE AIR INTAKE DUCT PASSES OVER THE TOP RADIATOR HOSE.NOW WHEN ALL COOLANT DRAIN OUT.LOOSEN UPPER AND LOWER RADIATOR HOSE CLAMPS.THEN DETACH THE RADIATOR HOSES FROM THE FITTINGS.IF THEY ARE STUCK GRASP EACH HOSE NEAR THE END WITH A PAIR OF ADJUSTABLE PLIERS AND TWIST IT TO BREAK THE SEAL THEN PULL IT OFF REMOVE SMALL COOLANT SURGE LINES FROM TOP OF RADIATOR THAT GOES TO THE OVER FLOW RESERVOIR..DISCONNECT COOLING FAN ELECTRICAL CONNECTOR.THEN REMOVE THE COOLING FAN.REMOVE DISCONNECT AUTOMATIC TRANSMISSION COOLER LINES GET READY TO CATCH TRANSMISSION FLUID THEN PLUG LINES. NOW UNSCREW THE FOUR BOLTS TWO ON EACH SIDE OF THE RADIATOR THAT ATTACH RADIATOR TO THE AIR CONDITIONER CONDENSOR CAREFULLY TIP TOP OF THE RADIATOR SLIGHTLY TOWARDS THE ENGINE.REMOVE THE UPPER RADIATOR SEAL AND LIFT RADIATOR FROM THE ENGINE.NOW IS THE TIME TO REPLACE THE UPPER AND LOWER RADIATOR HOSES WITH NEW ONES SINCE ALL COOLANT REMOVE I WOULD REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP.NOW WHEN YOU GET READY TO INSTALL NEW RADIATOR USE SHEETS OF CARD BOARD PROTECT RADIATOR FINS AND CORES FROM DAMAGE WHILE SITTING RADIATOR BACK IN PLACE.ONCE YOU GET UPPER AND LOWER HOSES IN PLACE ALSO PLACE SMALL SURGE HOSES FROM THE OVER FLOW RESERVOIR TO RADIATOR NEW THERMOSTAT AND TRANSMISSION COOLER LINES ALL HOOK UP. START POURING ANTIFREEZE IN THE RADIATOR OR OVERFLOW RESERVOIR IF RADIATOR DONT HAVE RADIATOR CAP ON IT.POUR A FULL GALLON ANTIFREEZE AND A HALF MORE IF LONG AS THE COOLANT STAYS ON THE COLD LEVEL MARK ON OVERFLOW RESERVOIR DONT OVER FILL.IF YOU POUR ANTIFREEZE IN RADIATOR KEEP POURING ANTIFREEZE UNTIL LEVEL STOP DROPPING AND LEVEL OFF AT RADIATOR TOP.START ENGINE CHECK FOR LEAKS. LET ENGINE RUN UNTIL IT WARM UP TOP RADIATOR HOSE GET HOT.WATCH COOLANT LEVEL IN RADIATOR OR COOLANT OVERFLOW RESERVOIR WHEN THERMOSTAT OPENS COOLANT LEVEL WILL DROP.ONCE YOU HAVE ENOUGH COOLANT IN THE SYSTEM COOLANT LEVEL WILL STOP DROPPING.THEN YOU READY TO GO.LET ENGINE SIT A LITTLE WHILE CHECK COOLANT LEVEL AGAIN.COOLANT LEVEL IN THE OVER FLOW RESERVOIR SHOULD BE AT HOT MARK FOR HOT ENGINE AND WHEN ENGINE COLD COOLANT LEVEL SHOULD BE AT THE COLD MARK.IF POUR ANTIFREEZE IN THE RADIATOR COOLANT LEVEL SHOULD BE AT TOP OF RADIATOR BELOW PRESSURE CAP.

Seek mechanical assistance, sounds as if head gasket of crack possible due to over temp

This is how I like to do it. Make sure the car is parked with the front end at an upward angle. Drain the coolant from the petcock at the bottom of the radiator. Remove the upper and lower hoses at the radiator. Remove the thermostat housing, and the heater core hoses at the fire wall. Flush out the radiator by pouring fresh water into the overflow, and the hole where the thermostat was. Flush the heater core as best you can by pouring fresh water into the heater core hose connections.
Let all the water drain out, then button everything back up and replace the thermostat with a new one. Refill the rad and engine by filling the coolant reservoir with a mix of 50% water and 50% antifreeze, or buy the premixed stuff from the auto parts store. (Buy 4 jugs of premix or 2 of straight antifreeze)
Run the engine until it reaches operating temperature and the upper rad hose gets hot. Rev the engine a little to help get the air out of the cooling system. When the thermostat opens, the coolant level will drop in the reservoir, so top it up and replace the cap.
Check for leaks, and check the coolant level for the next few days, and check for leaks.
Dispose of the old coolant responsibly

1997 Plymouth Neon, have replaced radiator, radiation cap, thermostate and hoses, still run hot. Fans do not seem to come on, where is the temperature sensor on this vehicle?

If the coolent level is good and the reservoir is full or has coolant backing up into the reservoir, then it's a stuck thermostat.

actually it is not good idea to replace your coolant by water only you shoul full your coolant system 50/50 mixture coolant and water because coolant has uniqe smell and color so easier to identified leaks.
first check your oil condition and coolant reservior for any coolont oil mixture for figure out head gaskets condition if you have any oil coolant mixture in oil or coolant you have a blown head gaskets this will send you to mechanic if everthing looks clear then go front driver side bottom of radiator and open the drain **** (make sure car is cool and put container under because coolant is toxic and mess up your drive way )open reservior tab too and drain all the water close back drain **** probably your vehicle prefer dexcool(red color)
fill 3 qt dexcool then water or just buy ready mix run the engine with reservior tab open and check coolont level add more if necesery suquize collont hoses for air inside when engine start hit up close reservior tab. on passanger side front of the engine has a coolant drain plug open with number 8 wrench untill you see the coolant come out( bleed the system for air) make this several times turn on your heat too and bleed again and watch your upper and lover hoses for any visible leaks fallow small coolant lines like under throttle body check thermostat housing under throttle body on 3.4l engines check under radiator if your pressure cab dosen't look good get a new pressure cab .shut of the car and check for leaks once you find out where is leak from easy to fix it.

Remove coolant reservior and clean out use a degreaser type soap like dawn