98 Beetle overheating

My 98 beetle is overheating and the fans are not coming on. Although with the A/C on they both come on. Still overheats with a/c and both fans running in idle. Any help would be appreciated.
Thanks,
Anthony

Does the lower radiator hose and radiator get hot (as hot as the upper & cylinder head), possible stuck thermostat? Does the water appear to be circulating, possible water pump. I've heard of a few cases of the impeller blade coming loose.

yes my thermostat does open up and let the water go in and the mechanic working on it says the water is circulating. Changed the fan thermo switch that is on the radiator and that didn't solve the problem. Now on the diagnostic machine the temperature read -40 f even though it was overheating so I am going to try the coolant temperature sensor.

That should do it.