I've searched pretty extensively and found several posts that are ALMOST the same as my problem -- but not quite...
My '96 LS400 runs very well and is well maintained. But I've noticed that when I go on a long trip (two hours or more -- it usually takes quite a bit more than that), my heat or A/C airflow fades and eventually quits blowing. It's not a coolant level issue -- it does the same with A/C as with heat. Different RPMs don't make a difference either. In order to get the control back, the car has to sit for a period of time (sometimes stopping for lunch will make it 'all better', and sometimes it requires an over-night stop.
Just driving around my normal daily life, it never happens -- so of course, I can never get it to my mechanic while it's acting up because I have to be several hours from home before the problem ever shows up!
It would be my guess that the problem is located in a control that directs an airflow 'door' somewhere. When the problem occurs, you can hear the fan running as normal (responding aurally to manual adjustments in fan-speed). But the air quits flowing from ANY of the vents. The air always comes from the correct ports (defrost, face, feet) when it IS flowing. But when the problem surfaces, the air-flow simply tapers off to nothing.
It's really maddening since this car is my preferred driver, and it's BEAUTIFUL for long trips -- except for this! If it's during the need for A/C, it's merely an inconvenience, as I don't mind driving with my windows down for a while. But when it's cold out (like on our trip home from our daughter's place more than three hours away last night), it can become a hazard, since I have no way to provide ANY airflow to the windshield, and keeping the windows from fogging up can become very challenging. (Especially with two adults and two dogs, like I had last night...)
Anyone else every experience this? With winter here, I really need to find a way to address this. But since I can never experience the problem except when I'm a few hundred miles from home, it's never practical to get it to my mechanic to examine things while it's acting up!
Thanks in advance for any advice or shared experience...
Recently, my battery died on my 2010 ES350. After jumping it, I noticed there's heat coming out of the driver's side (and rear) vents, but cold air coming out of the passenger's side vents. I checked fuses and everything seems to be fine. After some research, read that maybe the AC Blend Servo Door is stuck (or maybe I shorted it or something when I jumped it). Does anyone have any other thoughts/suggestions? Am I on the right track? If so, can anyone point me to a step-by-step of how to get to the blend door servo (I don't have a repair manual) to check or replace it?
My 2007 Lexus ES350 (105k miles) has the AC putting out warm air to the driver side while cool comes out the passenger side. The car is equipped with a Dual Zone capability. But this is happening when dual zone is off and the unit is set at "LO" or the coldest setting.
I thought maybe a system recharge is in order but one side is very cold. Maybe a fuse/relay/rubber pressure tube?
So I did a A/C refrigerant recharge today, and want to share some lessons learned.
My A/C is blowing cool air, but it can't keep up when it's 90 degree outside. I want to add some refrigerant to see if there are any improvements.
Before I go any further, I must warn you: if you didn't change oil yourself, or if you are very environmentally conscious, don't do this yourself. Take it to a mechanic and tell him about special caution for hybrid A/C system.
1. Hybrid vehicle need pure r134a refrigerant, or a refrigerant designated for hybrid vehicle use because the lubricant oil used is special hi-dielectric oil. Don't ever use oil for conventional vehicle. I bought A/C Pro HYB-134A R134a refrigerant refill, 10 oz size, containing 0.5 oz oil. If your vehicle still blow cool air, then 1 can is more than enough.
2. You need a A/C charging hose with gauge. Make sure the hose is long enough. RX400H need a 24 inch long hose.
3. Wear a latex or thin glove, ideally with long sleeve to protect your forearm from hot engine support brackets. An old long sleeve shirt works for me.
4. Turn car on, turn A/C on using the climate control, not the Auto setting button. Set temperature to Max Cool. Auto setting may or may not cut off compressor when cooling, so don't chance it. Turn the windows down.
5. Connect the hose to the low pressure port, following the instruction provided by the hose packaging. Make sure the valve for the refrigerant can side is closed.
6. Check the low pressure side pressure according to the temperature/pressure chart provided on the hose packaging.
7. If you need to add refrigerant, shake the can well, and retract the valve's piercing pin back, so that you can screw on the can to the valve tight. Turn valve clock wise all the way to pierce the seal.
8. Keep the can upright. Open the valve by turning the handle counter-clockwise. The refrigerant will turn into gas and be sucked into the A/C system. Shake the can, and every 2-3 second, turn the can to 3 o'clock position to drain some of the oil into the system.
9. Very Important: turn the valve off every 10 second to check the system pressure. Wait a few second to see the system pressure. When it's almost done, the pressure at the end will shot up very quickly, and lead to overfill. Take it slow and spend your time checking the pressure with the valve closed.
10. When the desired system pressure is achieved, turn the valve off completely. Don't try to get to the high end of the recommended pressure range. Remove the connector from low pressure port. Replace the dust cover onto the port.
11. If you overfill the system, STOP. The compressor will cycle on, then shut off due to cutoff switch in the system. You should do the right thing, turn off A/C, and drive to a mechanic to drain a little refrigerant out. There are advice on the internet on how to do this by inserting a long philips head screw driver into the port, depress the valve stem to release refrigerant. This is illegal because R134A is a greenhouse gas, even though not as bad as R12. The valve on the low pressure port is just like your tire valve stem. You depress the center to let the air out.
Note: The gauge for the recharge hose is not as good as the ones used by mechanics. It also don't have a good trigger valve, so this doesn't work as easily as the all-in-one system designed for conventional vehicle that you can buy in the auto parts store. Don't ever use those kits because it will contaminate the hybrid A/C system with oils that will conduct electricity.
The refrigerant I used claim to seal leaks too, and it works by conditioning the rubber seals, not by plugging up the seals with goo. People who had used it claim it worked on slow leaks over time.
It's 90 degree outside today, and my car's A/C provides a cooler breeze than before. It's not super cold from the vent, but I heard that the system on RX400h always blends some warm air with the cold.