Cooling fan not coming on, 2004 Honda Civic?

Sorry for the repost but I wanted to add a pic of what I've replaced 2 times, we did it just in case the first one we bought was broken some how since it still wasn't working after we put it in. The fan won't come on and the car is over heating. The fan and relay are both working when we test them with a wire, not sure what else it could be.

Added (1). Edit: we had just changed the thermostat a couple weeks ago while the fan was still working fine on it's own. This problem started last week

Rnaybe you should have a rnechanic take a look at it

Sounds like a common problem which needs a specialized fix.

https://www.ifixit.com/...+civic+car

This could be better
https://www.civicforums.com/forums/329-engine/329011-2004-radiator-fan-not-working.html

First step is to see if the fan actually works. You can use a Power Probe or relay bypass switch or even a fused jumper wire. If it don't turn on, replace the fan. If it does, use theory, logic and a wiring diagram to trace it back to why it's not coming on. Could be anything from a faulty cooling fan to the PCM having a failed low side driver that's not grounding the control side of the relay.

Right now, you have no idea what sends the ground to the relay. Maybe the thermostat output goes to the ECU, then the ECU supplies the ground. Can't venture to say without a wiring diagram. You may need to buy a book or check the library for one.

Make sure the fan relay is not bad. Make sure the radiator is full.

You changed the thermostat? So you drained the coolant and put in a new thermostat? Then you did not refill it correctly and the area where the sensor is at is DRY.(and not submerged in hot coolant. Remember when you put in a thermostat, it is closed when cold so no coolant or air gets past it. So you refilled it wrong. Instead of filling from the coolant tank, take off an upper rad hose and pour in the coolant through the hose so there's coolant above the thermostat. Then reconnect hose and refill from tank which fills the bottom end of the engine. You car should take about a gallon of coolant/mix. The specs are in the owner's manual not in my head as I would have to remember 1000 different car/trucks and I'm not going to do that.

I did not have this problem on a Honda, but on a different make of car and THAT WAS THE REASON. Refill it correctly and NO PROBLEM.

If your driving was mainly open road driving then there's no reason the fan NEEDS to come on as the air is flowing through the radiator as you scurry down the highway, or in the rain or just making short drives. I can drive my car up into the hills on the highway and back again(100 miles circuit @60MPH and the fan NEVER COMES ON and I never overheat because the air flow is sufficient to cool the coolant. But if the drive is bumper to bumper slow moving traffic then there's no wind blowing past the radiator fins, so as it heats up, the fan kicks on., for awhile… And then clicks off… When engine temperature is cool enough.
Pay attention and you will notice this is how this works.

When the temperature gauge fluctuates up and down it's due to an air pocket in the cooling system.
Run the motor for 15 minutes with the radiator cap off and watch for air bubbles coming out of the radiator neck. Top up the coolant as the air purges.
If the air bubbles never stop… Or if the coolant blows out of the radiator it's time to do the head gasket which is bad. If you do it yourself you'll need to take the head to a machine shop to be pressure tested to make sure the head isn't cracked.