Radiator fan always on?

LISTER89

MEMBER
2004 HYUNDAI SONATA
V6
2WD
AUTOMATIC
217,000 MILES

My radiator fan is on constantly. To the point where the bushings are now worn out and it is really loud. I tried unplugging the relays, but it keeps going. Any ideas? I know I'm going to have to replace the fan but it's just going to happen again if it is constant like this.

5 Replies

BRENDON S

MECHANIC
653 POSTS

Good morning, LISTER89,

My information is telling me your vehicle is equipped with 2 fans.

Do both fans run or just one? If it is just one, is it the driver's side or passenger side fan?

Also, what does the temperature gauge look like when fully warmed up and the fan(s) running? Does it look normal?

Any other issues lately?

Thank you,
Brendon

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Sunday, April 2nd, 2023 AT 5:28 AM

LISTER89

MEMBER
14 POSTS

Only the driver's side fan is ever on. And the temperature is just under half. Other than needing a tune up, no issues.

Was this

answer

helpful?

Yes

No

Sunday, April 2nd, 2023 AT 6:06 AM

BRENDON S

MECHANIC
653 POSTS

Hello LISTER89,

I am including a diagram of the under-hood fuse and relay panel and have highlighted the radiator fan relays. Are these the relays you removed?

Thank you,
Brendon

Image (Click to make bigger)

Was this

answer

helpful?

Yes

No

Sunday, April 2nd, 2023 AT 6:55 AM

LISTER89

MEMBER
14 POSTS

Didn't see the top one before. I started by removing the top one, then the bottom left. When I removed the bottom right, it turned off. So, I plugged back in the top one and the bottom left only. And it stayed off. Only when I plug in the bottom right one again does it turn back on immediately. Does this mean it's a bad relay?

Was this

answer

helpful?

Yes

No

Sunday, April 2nd, 2023 AT 8:13 PM

BRENDON S

MECHANIC
653 POSTS

Good morning, LISTER89,

It sounds that way to me but let's verify just to make sure. Take the bottom left and put it in the bottom right position and see if the fans stay off. They should be the same relay and should have the same part number stamped on it.

If the fan stays off, then it's the relay.

Let me know what happens.

Thank you,
Brendon