The fans should come on when the engine temp hits about 215. The coolant temperature sensor (CTS) should have a resistance of 180 ohms at 212 degrees. The resistance would have to be around 160 -170 ohms to turn on the fans. Since both of your sensors are reading 200 ohms at 215 degrees either both sensors are bad or the engine wasn't as hot as you thought.
You could go to Radio Shack & get some resistors to experiment with. Connecting a 180 ohm resistor to the wires for the gauge'* CTS will show the point where the fans are about to turn on. Connecting a 160 ohm resistor to the wires for the PCM'* CTS should turn the fans on in low speed mode. Connecting a 130 ohm resistor should turn the fans on in high speed mode.
1999 Pontiac Bonneville SSEi (son'*)
1997 Chevy Lumina (daughter'*)
2006 Chevy Trailblazer (wife'*)
2006 Chevy Monte Carlo SS (Mine! -Zoom Zoom Zoom)