2005 Heat gets COLD when it gets 'caught up'
Thread Starter
Intermediate
Joined: Mar 2015
Posts: 355
Likes: 47
From: North Carolina
2005 Heat gets COLD when it gets 'caught up'
Hi all 2005 BASE Model with 90k miles.
Its been bitterly cold in Midwest. This is really my first full winter. When the heat gets up to the selected temp, The car becomes COLD. In my old truck there was a resister known to wear out for low speed on the blower.
Do folks have the same sort of feedback? If the heat cuts to low speed, essentially theres no longer air output at that point.
Heat is very warm as it catches up, so overall the heater core works fine. Just low speeds seem to have nada air output.
It sat out in -25 for probably 36 hours, so driving the colder air is more noticable!
PS my 2004 didnt have the same issue :-) Cabin was always very comfortable.
Its been bitterly cold in Midwest. This is really my first full winter. When the heat gets up to the selected temp, The car becomes COLD. In my old truck there was a resister known to wear out for low speed on the blower.
Do folks have the same sort of feedback? If the heat cuts to low speed, essentially theres no longer air output at that point.
Heat is very warm as it catches up, so overall the heater core works fine. Just low speeds seem to have nada air output.
It sat out in -25 for probably 36 hours, so driving the colder air is more noticable!
PS my 2004 didnt have the same issue :-) Cabin was always very comfortable.
Racer
Joined: Apr 2009
Posts: 1,358
Likes: 87
From: Delaware
I had a heating issue several years ago. No heat from the floor nor vents etc, even though the car was fully up to operating temperature. I don't remember if the fan also didn't run or if the fan was blowing cold air. This issue was intermittent for 1 day then disappeared and haven't had the issue again. I'm assuming it was air in the system, but I hadn't done any drain/fill of the antifreeze/coolant. Weird. Glad it's never happened again.
In your situation, it sounds like you described you have NO AIR when the fan is set to low? When you manually turn the fan to a higher speed, you DO have air flow, and it's hot? If that's the case, then you're on track with the resistor package. (In my 2004 F150 I had the identical problem!), and it was the resistor pack which cost me about $40 and I replaced it myself.
Curious, I just looked at some Lexus parts online, and found the resistor pack aka blower motor control module, for the REAR HVAC system (ultra models), but didn't see any resistor pack/circuit boards for the normal/front HVAC system? Could it be a defective AMBIENT AIR SENSOR? What happens if you set the temperature to 80deg instead of turning up the fan speed? Can you hear the fan increase in speed and temperature?
Hopefully someone else will chime in.
In your situation, it sounds like you described you have NO AIR when the fan is set to low? When you manually turn the fan to a higher speed, you DO have air flow, and it's hot? If that's the case, then you're on track with the resistor package. (In my 2004 F150 I had the identical problem!), and it was the resistor pack which cost me about $40 and I replaced it myself.
Curious, I just looked at some Lexus parts online, and found the resistor pack aka blower motor control module, for the REAR HVAC system (ultra models), but didn't see any resistor pack/circuit boards for the normal/front HVAC system? Could it be a defective AMBIENT AIR SENSOR? What happens if you set the temperature to 80deg instead of turning up the fan speed? Can you hear the fan increase in speed and temperature?
Hopefully someone else will chime in.
Thread Starter
Intermediate
Joined: Mar 2015
Posts: 355
Likes: 47
From: North Carolina
Yes setiing a temp- which is what I normally do-car heats up great.
As it gets warm and the HVAC backs down- it feels cold in certail spots like the outer areas - obviously the doors.
As it gets warm and the HVAC backs down- it feels cold in certail spots like the outer areas - obviously the doors.
Racer
Joined: Mar 2018
Posts: 1,282
Likes: 384
From: ESSEX, UK
I've found in colder weather that it helps to increase the Set temperature by a degree or 2 as the system lags a little.
There is a setting in Techstream (SET TEMP SHIFT) that can be used to fine tune the actual vs displayed temperature.
Also, if set to Auto, the system will switch between Recirculate and Fresh Air at will, so you could be feeling where it switches to Fresh Air at -25. :-)
However, since it never gets to -25 here it could be something else entirely. At those kinds of temperatures all kinds of weird things happen.
There is a setting in Techstream (SET TEMP SHIFT) that can be used to fine tune the actual vs displayed temperature.
Also, if set to Auto, the system will switch between Recirculate and Fresh Air at will, so you could be feeling where it switches to Fresh Air at -25. :-)
However, since it never gets to -25 here it could be something else entirely. At those kinds of temperatures all kinds of weird things happen.
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