Radiator Fan always on ??
Evolved Member
Joined: Oct 2011
Posts: 524
Likes: 1
From: NH
To all the people that said thermostat... how could the thermostat be the problem if the fans come on right when the key is on? What is it, an electrical thermostat?? You have an electrical problem. I've seen bad coolant temp sensors do this. The fan is always on because there is an electrical problem somewhere, and the fan is staying on as a failsafe since it does not know what temp to come on at, so it just stays on, to prevent overheating. Just like when certain modules go bad sometimes, the wipers and headlights will stay on for example, as failsafes for the car, as if you were driving in the rain, or if it were dark at night.
Evolved Member
Joined: Oct 2011
Posts: 524
Likes: 1
From: NH
UPDATE!!
Like I said before, the fan switch and the fan module are fine
When I remove the relay from the fusebox, the fans stop
So after I removed the relay, I checked the female side (the part that is on the fusebox where the relay is plugged into), and it is getting a consistent ground
How can a grounding kit fix this?? As far as I know, the grounding kit connects to the + and - on the battery and the other grounds connect to the engine block, fuel rail and intake manifold...
Like I said before, the fan switch and the fan module are fine
When I remove the relay from the fusebox, the fans stop
So after I removed the relay, I checked the female side (the part that is on the fusebox where the relay is plugged into), and it is getting a consistent ground
How can a grounding kit fix this?? As far as I know, the grounding kit connects to the + and - on the battery and the other grounds connect to the engine block, fuel rail and intake manifold...
no. but i have a secondary button fixed, to switch it off..
Probably not the same in an EVO but i has this issue in my 2G DSM and it turned out to be a blown driver or something to that effect in the ECU. Tom at ECMTuning fixed it for me. No idea who can do that for EVO ECUs though.
so, the general consensus seems to be that the ECU is messin up here?? is it something with the hardware or is it the programming?? i'm gonna have my ECU reflashed this week at AMS so hopefully they can shed some light.
To all the people that said thermostat... how could the thermostat be the problem if the fans come on right when the key is on? What is it, an electrical thermostat?? You have an electrical problem. I've seen bad coolant temp sensors do this. The fan is always on because there is an electrical problem somewhere, and the fan is staying on as a failsafe since it does not know what temp to come on at, so it just stays on, to prevent overheating. Just like when certain modules go bad sometimes, the wipers and headlights will stay on for example, as failsafes for the car, as if you were driving in the rain, or if it were dark at night.
+1 Your coolant temp sensor is bad.
Last edited by Tekniq; Jul 8, 2012 at 08:12 PM.
