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I've been dealing with an issue on and off for a couple months now. My radiator fan will run when the vehicle is off until the battery dies. My solution has been unplugging my battery then when I reconnect it everything is ok. Last night that method hasn't worked. My fan turns on as soon as I connect the battery. I had my thermostat changed and I also had a crack in my coolant cap so I changed that as well. Not sure what else it could be. I recently had my serpentine belt and water pump changed but the issue started right before that. Any clue what is going on or any troubleshooting tips to isolate the issue?
I drive a 2004 Acura TL. Located in MN where the temperature is around 65-85 degrees this time of the year
I swapped my radiator fan fuse with my heater fuse, connected the battery and no success. The fan is still running. The auto store is ordering me a fuse but I'm guessing I don't need it anymore, unless both of those fuses are bad.. Not sure what else to do
^..used to be the case with accords from the early 90's.
One way to test is to turn off the car, and while the fan is running unplug the coolant temperature sensor.
If the fan turns off then there is your problem. CTS is sending a bag signal.
you also have a condenser fan relay, radiator fan relay, in the under hood fuse box. So test them both by unplugging them when the fan kicks on and see which one cuts it off.
There is also a fan control relay in a multi relay box to the left of the underhood fusebox. It would be the relay on the left to test also.
Sorry guys got busy this week, Yes when I unplug the coolant fan fuse the radiator fan shuts off. So that means its a CTS problem.. coolant temperature sensor? I have no idea how to access that. I will do some more research.
As the weather started to cool down last year my problem went away and I forgot all about it. Now its almost summer and my radiator fan is running again. When I unplug my coolant fuse it stops. A few of you mentioned that I should change my CTS.
Does anyone know the steps or have any resources of how to change it? Can't find much for the 3G Acura
Can someone confirm that this is the sensor(3:51)? https://youtu.be/ZOTR3RPIsbY?t=3m51s
In the video he mentions another sensor behind the cylinder head. I don't have any engine light codes so I will be shooting in the dark with this fix
Hey ICeZero, the ECT, which is what your referring to (engine coolant temp) sensor is actually on the water passage, the thermostat is in the water passage. There is an electrical switch on the top side of the passage, with two wires going to it. It is close to the top radiator hose where the hose connects to the engine. I just did a complete picture job on the thermostat replacement. I've got to compile it and was going to post it in the how to section.
Hey ICeZero, the ECT, which is what your referring to (engine coolant temp) sensor is actually on the water passage, the thermostat is in the water passage. There is an electrical switch on the top side of the passage, with two wires going to it. It is close to the top radiator hose where the hose connects to the engine. I just did a complete picture job on the thermostat replacement. I've got to compile it and was going to post it in the how to section.
it's either a 14mm or 17mm wrench to remove it, I don't remember. It's on the top of the water passage and is a 2 minute job.
Hey ICeZero, the ECT, which is what your referring to (engine coolant temp) sensor is actually on the water passage, the thermostat is in the water passage. There is an electrical switch on the top side of the passage, with two wires going to it. It is close to the top radiator hose where the hose connects to the engine. I just did a complete picture job on the thermostat replacement. I've got to compile it and was going to post it in the how to section.
Ok Fulla, I will try to find it. Can you please ping me when you upload the picture. Thank you
What you need to check :
(photo from 2007-2008 manual, might be different)
(photo is upside down compared to your photo, fulla is right)
Your and "fixed" manual :
Spoiler
Both fans are working or only one ?
Problem with relays is that they are sometimes "sticking". Do you have multimeter with ohm or continuity checking (it beeps when two test leads connected).
So I plugged back in my cooling fan fuse(drivers side fan turns on) than unplugged the black 12V relay that fulla referred to and the radiator fan(drivers fan) stopped. Even after plugging it back in
Peter6: I do have a multi meter. You are suggesting to check the 2 relays circled plus the relay I unplugged/replugged
Turning the key to accessories with the air on, both fans work. If I swap the relays no difference. Its hard to reproduce the issue; since unplugging the relay the first time, the fan hasn't turned back on. I will drive around and try to get the car hot again. So I am assuming its the ECT unless there is more troubleshooting steps I can take
^..used to be the case with accords from the early 90's.
One way to test is to turn off the car, and while the fan is running unplug the coolant temperature sensor.
If the fan turns off then there is your problem. CTS is sending a bag signal.
Hey flyromeo3, what happens when the car is off and the cts is unplugged and the fan cuts on? This is what my car is doing. Any ideas?
Turning the key to accessories with the air on, both fans work. If I swap the relays no difference. Its hard to reproduce the issue; since unplugging the relay the first time, the fan hasn't turned back on. I will drive around and try to get the car hot again. So I am assuming its the ECT unless there is more troubleshooting steps I can take
Try disconnecting the plug from the ect, does the radiator fan come on? If it does and you plug it back in does the fan still run? To get it to cut off, start your car and cut your car off or pull the fuse. I'm having a similar problem. Hopefully together and with the help of others here we can get this fixed.
So I realized the relay on the left allows both fans to work without the relay on the right being plugged in, so I swapped them and unplugged the right relay and the fans didn't work. So I know now that one relay is bad. (hope that sentence isn't too confusing :P )
I will have to order an extra one because I am not sure if I trust the generic ones at the store without reading the datasheet. Hopefully this fixes my issue. If not next step is the ECT. I will keep you guys posted.
Also if I understand correctly, you are saying that with (left) AC condenser relay (??) both fans work. Even if right (radiator fan) is removed.
It should be true as :
(assuming FANH is not engaged/conducting, otherwise only AC fan will run on high setting)
Both of them should be running, but they will be slower. Also if you turn off climate control they will shut down.
In this case engine may overheat, as there's no engine fan relay.
If high setting will be engaged, radiator fan will cut off, and AC condenser fan will work on high setting.
So don't drive with any of the relays pulled off. Better to make engine too cold than too hot.
Also if I understand correctly, you are saying that with (left) AC condenser relay (??) both fans work. Even if right (radiator fan) is removed.
It should be true as :
(assuming FANH is not engaged/conducting, otherwise only AC fan will run on high setting)
Both of them should be running, but they will be slower. Also if you turn off climate control they will shut down.
In this case engine may overheat, as there's no engine fan relay.
If high setting will be engaged, radiator fan will cut off, and AC condenser fan will work on high setting.
So don't drive with any of the relays pulled off. Better to make engine too cold than too hot.
Agree with too cold vs to hot. On my car, if I pull the ect harness off, the radiator fan will run on high speed. Your temp gage inside the car will go all the way to high because its unplugged and not getting a True reading.
