Cold Air with Heat on
03-21-18, 07:36 PM
#1
Driver School Candidate
Thread Starter
Cold Air with Heat on
I'm experiencing a weird A/C heater issue. When outside temp drops the heat works great and I also have ice cold AC in the summer. But when outdoor temps are somewhere in the middle (40s and 50s) where I'd expect heat to kick in, unit blows cold air.
Ive searched all of the threads and haven't found this exact issue. Doesn't seem to be a servo mix since hot and cold both work. Could it be a bad fan clutch relay. This seems related to a thermostat or something reading outside temps. Any ideas here?
Ive searched all of the threads and haven't found this exact issue. Doesn't seem to be a servo mix since hot and cold both work. Could it be a bad fan clutch relay. This seems related to a thermostat or something reading outside temps. Any ideas here?
03-22-18, 05:19 AM
#2
Pole Position
Try running the A/C diagnostics and see if any codes are set:
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
03-22-18, 01:54 PM
#3
If you have it set at auto, and selected a temp of 72 ish and the temps outside are in the 40-50 and the sun is out...the sensor on the dash will cause the HVAC system, (while on AUTO) blow cool air out the top vents and warmer air down by your feet. Under the pretense that the sun is beating on you and it feels warm. See if bypassing auto and selecting just the bottom and turning up temp helps bring temp up,
03-22-18, 04:56 PM
#4
Driver School Candidate
Thread Starter
If you have it set at auto, and selected a temp of 72 ish and the temps outside are in the 40-50 and the sun is out...the sensor on the dash will cause the HVAC system, (while on AUTO) blow cool air out the top vents and warmer air down by your feet. Under the pretense that the sun is beating on you and it feels warm. See if bypassing auto and selecting just the bottom and turning up temp helps bring temp up,
03-22-18, 04:58 PM
#5
Driver School Candidate
Thread Starter
Try running the A/C diagnostics and see if any codes are set:
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
03-22-18, 05:46 PM
#7
Driver School Candidate
Thread Starter
Try running the A/C diagnostics and see if any codes are set:
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
https://www.clublexus.com/forums/per...ml#post3535684
Chip H.
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03-23-18, 06:41 AM
#8
Pole Position
I don't have any info on a 24. I would ask the dealer the next time you're there.
Chip H.
Chip H.
03-24-18, 07:27 AM
#9
You need to inspect the 06 sensors that is installed on GX. Room Temp Sensor. Air Duct Sensor. Evap Temp Sensor. Solar Sensor nd Room Humidity Sensor. Each sensor Resistance values need to be inspected nd measured. Normally The Thermistor No1 nd No 2 are the faulty ones . Even by slight touch by hand will change the values. . The Hint is as the temp increases, the resistance decreases. You need to use a Analog tester for resistance values.Normally this is the.part which fails. P/N 88625-35050 nd 88625-16210. Except Solar sensor inspection you need to cover the sensor with a dark cloth to avoid direct light to know the values. The value should read as infinite ohms( below 0.8V). And when exposed it shud read less than infinite ohms. That is around 4.3+/- 0.3V. Hope this helps
03-25-18, 02:56 PM
#10
Pole Position
Mann777 you really know your stuff about these vehicles! Thanks for sharing, I enjoy reading technical input like this. I know you have helped me in the past also, thanks for that too!
03-28-18, 03:10 PM
#11
Driver School Candidate
Thread Starter
If you have it set at auto, and selected a temp of 72 ish and the temps outside are in the 40-50 and the sun is out...the sensor on the dash will cause the HVAC system, (while on AUTO) blow cool air out the top vents and warmer air down by your feet. Under the pretense that the sun is beating on you and it feels warm. See if bypassing auto and selecting just the bottom and turning up temp helps bring temp up,
03-29-18, 06:43 AM
#12
Pole Position
(in Auto)
You should get hot air once the engine has come up to temp. The fan won't run until that happens so you don't get cold air blown on you. It'll run that hot air until the cabin almost gets to the set temperature, then it'll change the mix to blow only "slightly" warmer air. This is so you aren't bouncing between hot air - cold - hot air - cold. It's more gradual.
Chip H.
You should get hot air once the engine has come up to temp. The fan won't run until that happens so you don't get cold air blown on you. It'll run that hot air until the cabin almost gets to the set temperature, then it'll change the mix to blow only "slightly" warmer air. This is so you aren't bouncing between hot air - cold - hot air - cold. It's more gradual.
Chip H.
03-29-18, 11:25 AM
#13
turn the temp up,to high....it’s a thermostat like in your house, choose a comfortable temp and hopefully they system will maintain that temp by adjusting fan speed, outlet flow and air temp....not a perfect system in the GX, the last model is already 9 years old...sometimes you have to override the AUTO and make your own selection.
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jmbatule (03-29-18)
03-29-18, 12:33 PM
#14
Pole Position
Something I just thought of - I don't know if a dirty cabin air filter could affect the temperature sensor, but if it hasn't been changed in the past year, can't hurt to put a new one in.
Plain filter:
With activated carbon:
I strongly suggest you do NOT select the "With Installation" option (adds $225.00 to the price!!) Watch the Youtube videos on how to do it instead - it's easy.
Chip H.
Plain filter:
With activated carbon:
I strongly suggest you do NOT select the "With Installation" option (adds $225.00 to the price!!) Watch the Youtube videos on how to do it instead - it's easy.
Chip H.
03-29-18, 04:24 PM
#15
[QUOTE=chiph9;10157216]Something I just thought of - I don't know if a dirty cabin air filter could affect the temperature sensor, but if it hasn't been changed in the past year, can't hurt to put a new one in.
Plain filter:
With activated carbon:
I strongly suggest you do NOT select the "With Installation" option (adds $225.00 to the price!!) Watch the Youtube videos on how to do it instead - it's easy.
Chip H
Dont Think that would affect temo, , just airflow, I’ve seen some pretty clogged up filters on my kids cars and HVAC worked fine..
Plain filter:
With activated carbon:
I strongly suggest you do NOT select the "With Installation" option (adds $225.00 to the price!!) Watch the Youtube videos on how to do it instead - it's easy.
Chip H
Dont Think that would affect temo, , just airflow, I’ve seen some pretty clogged up filters on my kids cars and HVAC worked fine..