Hello all!

I have a 2004 Hyundai Sonata and the Cooling and Ac fans are not operating. Even when the AC is on, the fans don't work. I changed the fans 2 days ago,
so now they are brand new, and they still do not operate. I just don't know what would cause the fans not to operate if the AC is turned on. If I could get help figuring this out
I may be able to get my wife's car back on the road. Please help and thank you!

 

Check the fuses

 

I checked the fuses, and relays. Everything works. The fans still are still not operating. I have to also mention that I changed the fans and that did not solve the issue either.

 

When you turn on the fans (by turning on the AC), did you measure any voltage at the connector going to the fan?

 

I don't have anything to measure the voltage unfortunately.

 

Could use a test light? When it lights you know you got power when clip is ground
Or you know you have ground when it lights and clip is to B+.

 

I just bought a Voltage meter and it should be here tomorrow. Are there any tips on how to use it to check the fans?

 

Personally, I like using a test light (not LED).
Test lights tend to load the circuit a little.
Testing circuits should be done under load
Corrosion does funny things to circuits and can cause misleading readings.

Anyway, voltage test at the connector to fans.
See if there is power going to the fan.
See if there is ground to complete the circuit.
Recently saw where testing with a volt meter showed 12 volts.
Continuity checks showed good ground.
Garage replaced the fans and they still did not work.
It turned out to be a bad ground.

 

I see that there is a technical bulletin and a repair kit for the fan connector on this model of Santa Fe (I see you have a Sonata, but this could still be applicable). Your problem might be there. If you have voltage on the engine harness connector but none on the fan side, the connector is bad. I have this problem right now and have ordered the fix kit from Hyundai. You must cut and solder in new pigtails (but probably not on your new fan). If you can't do it, get an electrical guy that can. Below is a picture of my burned up fan connector. The Hyundai repair kit is part# 912002-6000FFF. I would replace the fan relay too since the contacts may be burned (cheap insurance). Info here: https://www.brakeandfrontend.com/tec...ng-concerns-2/ Caution! Sonata may use different connector!

 

The OP (Original Poster) has not been here to update his situation for a while
So would assume he either fixed it or got rid of the vehicle