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So this has been an ongoing issue but have come to a dead end. There are a lot of posts similar and with great info but I still can’t track this down. My cooling fans only run together both with ac on and off. Ac off both fans will come on around 217 and stay on to 180° consistently hard driving, sitting in traffic or just idling so I don’t think it is an issue with the cooling system itself. This has been ongoing since I got the radiator replaced a few years ago and since I don’t daily the car it has kind of been put off or I would just run the ac if I felt I was getting too warm. Readings are from a scan tool so I trust fairly accurate. Already shot the parts cannon at the issue and have in addition to a new radiator replaced fan switches A&C the ect sensor drained and flushed coolant and replaced stock thermostat and cooling fan timer. Does anyone have any advice on tracking this down? I know the drivers fan should cycle on and off at idle and come on around 203 or so but it isn’t doing this and also fans seem to only run at lower seed when powered from power probe but I’m only putting out 12v and that may be the issue. Please? Lol at a total loss and only really thing left to address in getting her 100% put a lot of time Into other issues and just want to know she’s right, doesn’t over heat as gauge never moves past a few below center, 7 lines visible I believe maybe 8 and scan tool shows steady at 180 on highway or moving and only warms up sitting still or heavy traffic.
BryanD,
I want to make sure I understand what you are concerned about; it seems that the fans come on but at 217F and your concerned that is too high? Is that correct?
See picture below. As you can see the temperature for the switches are a range not an absolute. Does this help?
Exactly, i feel 217° is a little too warm and even though i can keep it below this temp and it cools efficiently just doesn’t seem right. If we are talking about the same manual I have gone through and done all but test continuity of the switches in hot water. I get continuity at correct temps but fans just dont want to kick in below 217°. Im not sure if it is based on fan controller logic or not, my going theory for a while was that it was using some combination of sensors ie c reading cold at the bottom of the radiator will prevent fans from cycling before it feels it’s needed. Just some more info, jumping the pins at fan switch A runs both fans not just one which also seems odd to me, haven’t jumped B but based on temp it comes on seems to be working and C alone will not turn fans on. Don’t think I mentioned either all new relays for fans as well. I’m curious which troubleshooting info you have and if it’s different than in my manual. Any help is much appreciated
Already shot the parts cannon at the issue and have in addition to a new radiator replaced fan switches A&C the ect sensordrained and flushed coolant and replaced stock thermostat and cooling fan timer.
Just curious, was the replaced ect sensor OEM?
BTW, is your TL a Base model or TL-S?
It’s an 03 tl type s, I believe it was a Delphi denso or wve not from Honda but as far as I know it was same manufacturer they use, replaced quite a while ago maybe 2 years. Was a higher end replacement for sure.
BryanD, The manual I am referring to is the service manuals. If you don't have them here is a link were you can download them. https://www.dropbox.com/s/alzlpd489p...ANUAL.pdf?dl=0
There are troubleshooting guides for different sets of symptoms for the fans turning on for both the radiator and condenser fans symptoms. I believe that the radiator fan should be on earlier than 217F but aftermarket sensors are usually designed to be used in as many vehicles as possible.
It looks like Zeta has a thought hopefully he will get back to you with something more specific.
It looks like Zeta has a thought hopefully he will get back to you with something more specific.
More like a wild guess 'hunch' and the personal experience that, when it comes to replacing sensors for these cars, I always pay the $$ for OEM (ie fuel relay; trans speed sensor; 3 & 4 gear trans. sensors etc).
I agree. There are items that can be generic but some items you just have to go OEM. Sometimes you can find the manufacturer part but sometimes you just have to pay the full rate. Sensors can be finicky.
BryanD you can pull the sensor and heat it up on the stove in a pot of water while monitoring the resistance. I believe this is a switch so once it reaches temperature it should open up and resistance so be a short once it is activated when it reaches the temperature for which it is set.
I’m leaning towards ect being the issue although doesn’t fully make sense to me, OEM thermostat and it holds 180° as I’m driving or after a cooling cycle so while possible it’s off seems odd it holds right, whatever the temp really is it’s steady. Could definitely be reading wrong at higher temps, fan switch A does get continuity when warm but can’t be sure of the temp, a good bench test is a great idea as well. I really suspected the fan timer controller but it was replaced with a brand new OEM Motorola timer, relays and all but fan switch c are OEM Honda so replacing the ect and fan switch C is probably my next move, probably drain and flush coolant again and replace ect switch A and C OEM and bench test before Installation. If this fails what do you guys think?, am I being paranoid, how concerned about that heating to that temp would you be? Kind of considering just wiring the radiator fan only to constant power of all else fails, bad idea in you guys opinion? Any ideas about how much power should go to the fans for low speed vs high, another theory I have is the fans are wearing out and responding to higher voltage only but running slower, maybe the signal at 196-203° isn’t enough to spin the fan? I also have kind of thought maybe the fuse for the radiator is bad, i know it’s in the cabin and has been replaced but maybe it’s bad contact? Suspect this because I think the way the controller works if it didn’t have ground for fan switch A it will use ground on condenser end when it reaches that high of a temp. What do you guys think, any advice is greatly appreciated. Thanks for the help so far!
Whitetiger5 broke it down nicely, As mentioned before please check the manual for troubleshooting procedures. Also if you suspect a fan is wearing out you can wire directly to the battery and check see how the fan turns. It would turn faster with the car running as the voltage would go to ~14.4v. The battery has much more current available to power the fans than I suspect is available through the power probe you mentioned.
05-30-2022, 07:44 PM
