2003 Voyager cooling problem

My wife drives a 2003 Voyager and tonight a problem sprang up on her. The temperature gauge went all the way to hot and when she stopped, noticed that neither cooling fan was going. Also, the floor on the driver and passenger side has been wet for a couple months now. I figure with the temperature/fan problem and the wet floor that the heater core is leaking. Would the fans stop working if the coolant was below the temperature sensor? Also any tips/hints/tricks before I go elbow deep to tackle the problem. When she got home, she said she had to add water to both the radiator and overflow tank. I work on all my vehicles - having rebuilt a 1980 Econoline and 1972 Beetle. Just wanted to get a little more insite to what I will be up against here.

We have trod this ground before, but it is a common or seems to be common issue. First, turn on the AC and see if the fans run (fan is alwys hot in AC mode), if not,disconnect the electrical lead from the fan motor and then run a hot wire from battery +post and a ground wire from battery - post to the fan motor electrical hookup and see if the fan runs (checking the fan motor by hot wiring). If fan does not run I would assume a bad fan motor, if fan runs then the relay may be bad (located on lower cross brace of farme behind radiator and in front of condensor) ot the temperature sensor, located right below or next to the thermostat housing. I had a sensor get wet and short out and until she was dry, the fans would not work. Keep us in the loop.

The problem was the heater core!!! The cooling fans were not running due to the level of the coolant in the radiator was below the sensor. I bypassed the heater core until I can find and afford a replacement. Refilled the radiator and overflow and both fans run. Did some searching on the web and the cheapest I found was $133. The local parts stores (Auto Zone, Advance Auto, etc) all carry the rear core <If your vehicle has a rear heater - this one does not> but no one has the front core. Haven't been to the dealer yet to price the core (or taken it to have the power steering hoses replaced because of a recall). Thanks for your assistance.