My ‘02 RX300 has a vent issue.
I, recently changed the blower motor.
When I put the car back together, I couldn’t get much more than a weak airflow and that was with everything on full blast.
Everything pointed to the Air Vent Door Actuator or Servo so I replaced that as well.
I watched as the servo moved from position to position as I manipulated the dash controls. It works perfectly. As weak as the airflow is, I could tell the Servo was moving vent doors because there were slight changes that followed my command.
The blower runs as hard as the original so the system is getting plenty of air.
The air is going somewhere before it hits the vents.but where? I could use some advice.

 

So what was done to determine where the air is leaking. If the blower is working hard, there is got be a leak or major open, Dont forget to check the synchronization of Mode actuator is correct and dont overlook the defrost (air going to the windshield).

You should also reexamine if the motor is sitting proper in the cage.

Salim

 

I'm guessing you replaced the blower because low air flow?
If so plz pull cabin filter and Like salim says air going somewhere or you may have a restriction. Does it sound restricted?
Did you try on Recirculate?

 

What do you have to do to pull the cabin air filter? I'd like to check mine. Thanks!

 

Cabin filter replacement should be in the owner's manual. Should be checked every 3 months.

Going by memory here:
Process is to remove a panel by sliding it sideways in the back of glove compartment. Keep track of the up direction as it may give you trouble on reassembly [you can't get it wrong but just aggravating to flip and turn]. Once the panel is removed filter is right there and you pull it out. The filter sits in a frame and you have the option of changing every thing or just the filter element. There are two types of elements, one with and one without activated charcoal.

Leaves from the cowl can get in there and at least one member has reported it to be clogged.

Salim

 

I replaced blower motor because it was making noise. Blower motor installed correctly. Air direction servomotor replaced with cam positioned correctly. I have visual on servi as I manipulate the dash control and it is working correctly. No obvious obstruction.
system at full speed sounds exactly as it did new. Lots of air pushing through but, before it gets to vents, it’s...I don’t know where it goes. I checked everywhere I had access to and nothing. It’s like it’s swirling around inside the dash. Somewhere, along the way, it escapes.before it gets to vents. You would think I could hear a breach like that. The sound of air forcing its way out but nothing like that is detected. It’s getting to 105°-106° here and it stands to get hotter. I need to figure this out. Any help much appreciated.

 

Just a guess but you may have "leakage" by a servo damper being in between positions.
There is diagnostic mode you can do that will step thru and check the servos(actuators) and position sensors and display a code for errors found.