The radiator fans turn on when the engine starts and do not turn off. No problem getting heat, but the temp gauge tops out at 1/4, used to be 1/2.
The issue seemed to start after I replaced the air bleeder housing (with new temp sensor), so could the sensor be off? But why would the fans turn on if the engine appears to not warm up enough?
Maybe the fan relays are bad?
Just replaced the thermostat, no change.
Thanks for any assistance!

 

if the issue was not there b4 u replaced an item logical conclusion
the issue seemed to start after I replaced the air bleeder housing (with new temp sensor),

 

If anything about this car was logical the thermostat would not be where it is.

Does the temp sensor in the bleeder housing only control the gauge, or does it also control the radiator fans?
If the fan relay is bad, could it cause the fans to always be ON?
Since the fans run constantly, is this causing the temp to not reach normal?

In short, what possibilities would cause this to happen?

 

You're right, this doesn't make a great deal of sense. There is only one source of information regarding coolant temperature, and that is the sensor you replaced. Its signal is read by the engine computer and is one of the factors controlling the fans, A/C operation and automatic transmission fluid temperature being other factors. The same signal is processed by the engine computer and forwarded to the body computer to control the readout of the temperature gauge. So you'd think that if the sensor was reading high enough to keep the fans on, the gauge would also read high.
All that being said though, if there's a failure somewhere along the line, the default is to turn the fans on to provide cooling in case of doubt.
So if the fans are running all the time, the chances are the computer is not happy with the signal it's getting from somewhere and is running the fans "just in case".
This might show up if you could hook the car up to the proper diagnostic equipment.
I doubt that the fans are making the car run cooler than it should. The thermostat should control that.
There's probably a pretty good chance that replacing the temperature sensing unit would fix the problem, especially since installing it seems to have precipitated the problem.
Could the fan relays be stuck on? Maybe. Not real likely, but not impossible. There are two fan relays, one for each fan, so it's not likely that both would fail in the same manner at the same time.

 

Hi,

I have similar issue, but my fans are off (replaced air bleeder too).

I need turn on the A/C in order to run fans .


What was your solution about this issue?.


Thanks,

Denis V.

 

The fans are not supposed to run all the time. They come on at a certain temperature of the coolant, also infuenced by other factors such as A/C use. If you are concerned, take it in to a shop that has the proper diagnostic equipment, but what you have described so far does not indicate a problem.

 

I replaced the air bleeder assembly (plastic thing with the sensor and bleed valve) but it came with a bad temp sensor, which I suspect was telling the fans to turn on constantly. Replacing the sensor pretty much fixed it.
Also had a hell of a time getting the air out of the cooling system after all this, It does not work nearly as easy as the repair manual states. Thanks Chrysler.

 

If you had searched the forum here you would have learned that you should not bleed the system through that bleed screw. It's probably all right to do so when the part is brand new but if the part is not new, turning the screw runs a very big risk of stripping the insert in the plastic base and causing a leak, ruining the part.

The bleed screw is made to enable the guys in the plant to fully fill the system with antifreeze and remove the trapped air in one shot. The system will bleed itself without using the screw over several heat-up and cool-down cycles, but of course you will need to add coolant to replace air that works its way out.

Nobody ever said it was a great system. Not sure why Dorman temp sensors are so far off but you're not the only one to report this.

 

Thanks,

replaced new Dorman Tē sensor for the old sensor pulled off (plastic water outlet must be destroyed in order to get off the sensor) and fans work O.K. again.


Denis V.

 

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