temperature gauge problem

i have a 1995 accord lx and my temperature gauge isn't really working right now.  The needle moves a little when i drive (more than 30 minutes) only up to the blue line.  I took the resistance for the temperature sensor and it is good, then changed the fan switch (didn't want to return part, thought it was a sensor). 
 
For one, could it be the temperature sender even if the gauge needle moves?  I'm kinda fustrated because the gauge still doesn't work and now the fan comes on whenever i drive, about 5 minutes maybe.
 
Secondly, i'm hoping my old fan switch was bad, that's why the fan comes on most of the time now?  Is it supposed to come on that often.  note: the fan would come on with the old fan switch installed, it would just come on after the car was turned off for a few minutes.
 
i hope this was clear enough and any help would be appreciated.

is the thermostat stuck open?  thought that wouldnt explain the fan always coming on...

the thermostat is fine.  I just found out that since i bought the fan switch from a local car shop (not genuine honda part), its probably set at a lower temp, that's why the fan comes on sooner than the stock switch.   

Which 'sensor' did you replace?  Which sensor did you check the resistance of?  There's 2 fan switches, 1 temperature sensor for ECU, & another sender for the gauge.
 
The fan switch in the thermostat housing (lower radiator hose, back near firewall) is responsible for switching the fans while the engine is running.
 
The fan switch near the upper radiator hose is responsible for switching after you turn off the engine.
 
There's a timer module under the dashboard that's responsible for choosing which fan switch to pay attention to.
 
In the head near the distributor there's 2 temperature sensors.  The one with a 2-wire connector is for the ECU.  The one with only 1 wire is the sender for the gauge.
 
They don't 'share' information among the different sensors in '95.
 

i initially tried to replace the engine temerature sensor for the ecu, but took the resistance and found it was working.  I replaced the fan switch next (thinking it was another ecu sensor), which caused the fan to turn on at a lower temp because it was a generic switch. 
I just changed the temperature gauge sender which was the problem and now the gauge works fine.

Thanks for all the help!