I replaced thermostat in which I noticed it was centered and old was off centered. I also replaced fan switch and fan still not coming on. I checked relay its good and I jumped fan it works so could it be the new thermostat?
Nothing to do with the thermostat. A couple of things to consider. If the vehicle has Air Conditioning or not is important. If your Civic did not come with Air Conditioning and you have juice to the relay and it is just not getting activated, the most likely reason would be a faulty ECT – Engine Coolant Temperature Sensor.
If you do have Air Conditioning there are a few more relays to check before assuming the ECT is bad. The condenser fan relay and the A/C compressor relay.
I have added both wiring diagrams to give you a better idea of what is involved. If all components check out, there may be a wiring issue to look at.