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Had my 2017 P150 since new, but recently i noticed a change in the way that the "Auto" setting works on the climate control. I noticed because i kept noticing that my hands and arms were getting cold, when on the same settings that i have used daily for years. I seems like the air coming out the vents is a lot colder than normal. I would typically have the AC button "On" and the system on Auto at a cabin temp of 24 degrees. This seemed to be a good balance to keep the air dry and the temp pretty nice.
First thing i looked at was the cabin filter, as i thought that perhaps restricted airflow could be impacting it. it was grubby, so i replaced it anyway, even though it was unrelated. I then looked at the servo motors i could see under the dash when i pulled out the glove box, and i can see the actuators operate perfectly for the vent-selection and the internal/external air, however I cant see where the actuator is for the heater-core/AC-core blend (assuming it even works this way?)
if I turn temp down , the AC most definitely makes the air COLD! so i dont think there is any issue with the AC core or blockages etc in that space. If i turn the AC button off and turn the heater up high, the air gets warm as expected. I will say that i can tell if it is my imagination, or perhaps the heated air isnt as HOT as it used to be? (this could be in my mind). but i made not of it, in case perhaps there was restricted air through the heater core and as such it wasnt warming the cooled air as much as it needed to?
for me to get a temperature that feels like i would normally use in the cabin, i seem to need to have the Auto climate temp set to about 28 degrees. If i do that, the air is less arctic and doesnt numb my hands, but it is still 'tepid' yet comfortable.
So question 1 : Is there a blend actuator between the heater and AC cores somewhere, and if so, is it something that i can easily see and confirm is operating properly without pulling my entire dashboard out?
doing some further reading, I believe that there are three thermisters in the car that relate to climate. The one near the radiator seems to be about the ambient air temp, and i am going on the assumption that if this was not operating correctly, the outside temp display on on my dashboard would be wrong? the temp reading is correct on my dashboard. so unless this sensor has a different function i am currently excluding this from the suspect list. (please correct if im wrong here)
I have found the thermister in the wall in the back of the car for read cabin temp reading, and the one on the dash behind the left of the steering wheel. (the latter is suspect number one). I cant for the life of me, work out how to get that out, even though i can access it by reaching behind the dash with my hand. it seems to have a blue pipe running from it, down to the AC unit, which i assume either blows or sucks cabin air across the thermister to make the reading accurate ?
I have one of those inexpensive little Bluetooth OBD tools and can see a huge range of temps, however as it is a pretty rubbish device, i am not sure if some of the dud readings it gives me are because it isnt correctly scanning the car, or if they are a bad reading. specifically, there is a temp measurement that is called "Ambient Temp for AC". I am wondering if that is what gets reported by that front thermister. that said, whatever it is, it is reporting "-40 degrees", which i suspect is just an issue with the OBD tool, as it tends to write that for other sensors that it is confused about.
I am starting to ramble now
but i am keen to hear if others have had this specific issue, and any advice on what to check, how to access things and other tricks. when searching forums and the general internet, it is hard to sift through 99.9% of all the other AC issues that have far more common faults to find this rather uncommon one.
would love to hear from you prado folks on this!
thanks in advance!
Floyd
First thing i looked at was the cabin filter, as i thought that perhaps restricted airflow could be impacting it. it was grubby, so i replaced it anyway, even though it was unrelated. I then looked at the servo motors i could see under the dash when i pulled out the glove box, and i can see the actuators operate perfectly for the vent-selection and the internal/external air, however I cant see where the actuator is for the heater-core/AC-core blend (assuming it even works this way?)
if I turn temp down , the AC most definitely makes the air COLD! so i dont think there is any issue with the AC core or blockages etc in that space. If i turn the AC button off and turn the heater up high, the air gets warm as expected. I will say that i can tell if it is my imagination, or perhaps the heated air isnt as HOT as it used to be? (this could be in my mind). but i made not of it, in case perhaps there was restricted air through the heater core and as such it wasnt warming the cooled air as much as it needed to?
for me to get a temperature that feels like i would normally use in the cabin, i seem to need to have the Auto climate temp set to about 28 degrees. If i do that, the air is less arctic and doesnt numb my hands, but it is still 'tepid' yet comfortable.
So question 1 : Is there a blend actuator between the heater and AC cores somewhere, and if so, is it something that i can easily see and confirm is operating properly without pulling my entire dashboard out?
doing some further reading, I believe that there are three thermisters in the car that relate to climate. The one near the radiator seems to be about the ambient air temp, and i am going on the assumption that if this was not operating correctly, the outside temp display on on my dashboard would be wrong? the temp reading is correct on my dashboard. so unless this sensor has a different function i am currently excluding this from the suspect list. (please correct if im wrong here)
I have found the thermister in the wall in the back of the car for read cabin temp reading, and the one on the dash behind the left of the steering wheel. (the latter is suspect number one). I cant for the life of me, work out how to get that out, even though i can access it by reaching behind the dash with my hand. it seems to have a blue pipe running from it, down to the AC unit, which i assume either blows or sucks cabin air across the thermister to make the reading accurate ?
I have one of those inexpensive little Bluetooth OBD tools and can see a huge range of temps, however as it is a pretty rubbish device, i am not sure if some of the dud readings it gives me are because it isnt correctly scanning the car, or if they are a bad reading. specifically, there is a temp measurement that is called "Ambient Temp for AC". I am wondering if that is what gets reported by that front thermister. that said, whatever it is, it is reporting "-40 degrees", which i suspect is just an issue with the OBD tool, as it tends to write that for other sensors that it is confused about.
I am starting to ramble now
but i am keen to hear if others have had this specific issue, and any advice on what to check, how to access things and other tricks. when searching forums and the general internet, it is hard to sift through 99.9% of all the other AC issues that have far more common faults to find this rather uncommon one.would love to hear from you prado folks on this!
thanks in advance!
Floyd
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