Within the last week or so I have noticed that the cooling fan seems to be activating itself sporadically when the car is warm. It spools up like an electric motor does when you connect it to a battery and then disconnect the terminals. It sounds like: Whhaaaaaa. Whaaa. Whaaaaaaaaaaaa. Wha. Wha. Whaaaaaa.

It does this independently of the main fan, and it seems to do it randomly once the car is up to temp and warm.

I took a video last night of my car idling. I had just started it and drove it around the block, so the car was warm but had not been driven hard.

The AC is NOT on, neither was the interior fan. You can see the dome light dim and then I pop the hood and you can see the fans kick on.

Please help me diagnose. Is it a fan relay or fan controller module? Skip to :25 and watch from there.

http://www.youtube.com/watch?v=cNSwa7dUfD4

Thanks!!! What do you guys think??

 

that's the radiator fan.. the a/c fan is on front of th radiator on passenger side.. the radiator fan does come on and off as temp changes..

 

Are you sure about that? The fan on the passenger-side front of the radiator is the fan that has always kicked on and been running. And it when the car needs to be cooled down it turns on, runs for 15 or so seconds, then turns off. (the passenger-side front fan). The fan that I show in the video has only been on if the A/C is on and until recently, never displayed the behavior that is shown in the video.

 

i just had to replace mine.. pass side is the a/c fan..

 

I stand corrected, I had no idea! What do you think the problem is with the fan? Post edited to reflect the correct problem. Thank you!

 

well as I said the fan does come on when the car is warm and hits a certain temp. then when cools down it shuts back off. as for the sound.. I know when my a/c fan went out, or bearings and became unlevel it made a god awful screeching whaa whaa sound.. so it is possible the fan is just going out.. but from listening to the video sounds fine.

 

Sorry but I have to ask, is the on-off-on-off-on-off thing normal? The car just started doing it.

Anyone with a second opinion?

 

it's normal.. just hitting the temp for the switch and it turns on. once cools down it goes of

 

It's also started turning on after the car is off. It just did it this morning.

 

Off as in key out or off as in the motor is off but the key is in the on position?

 

Key out of car, as I'm getting out of it. Fan does the stop-start-stop-start thing for several seconds. This just started happening.

 

It is the radiator fan relay box messing up.

 

You mean radiator fan control module right?? Because that is the part that fails most often on the fans. I had to replace mine because my fan was all sporadic like the OP said.

 

Fan control module. I read somewhere that this was a TSB on '05's. Is that correct? My car is out of warranty now but would Mitsubishi still replace the part?

 

Yes, it is a TSB for the '05s. If the car is out of warranty I believe it is up to the dealer whether they want to do it or not.