jcorava

My wife's 2012 RX350 is having a HVAC issue. The heater blower motor is not really responding - some heat is coming out, but not able to adjust the volume of air. On-line searches indicate a blower motor resistor to be the most likely cause (regulates amount of current to blower motor, thereby controlling amount of air blown).

I can't seem to find any information on-line about a resistor for this car. Any body know if this car has a resistor? Part number or place to purchase? Or any one know of other cause of problem?

Thanks,
Corey

Clutchless

It could also be a bad blower motor or (less likely) clogged cabin filter. When did you last check/change the cabin filter?
You can look here at the parts drawings to maybe find such a resistor and learn more about the system https://www.lexussouthatlantaparts.c...car-parts.html

You will probably need a shop to check this out.

salimshah

I am basing my answer on first gen ... this should help you search and confirm.

First gen uses a fan speed controller module. Resistors endup being very energy inefficient in dropping voltage. The controller module has active electronics to create less tan 12v to energize the fan. Typical life for this module is around 150k miles (12yrs) for gen1.

Salim

jcorava

Update: problem was a clogged cabin filter. We live in New England and the past couple weeks it was hella cold. Some murine S.O.B. decided to nest in my RX: he found a bag of cotton ***** and moved the whole lot in.

To help those in the future, here were my symptoms:
- low air flow, despite fan sounding a-ok
- climate control display did not show up on the LCD screen for ~ 25 seconds after starting
- other climate controls seemed work just fine (e.g. temp control, various modes)

What threw me was the second symptom - I figured there must have been an electrical component (e.g. bad fuse). Obviously, I underestimated Japanese engineering. Clearly the 25 second delay of climate display is a (airflow?) warning.

Lesson learned.

Clutchless

Similar thing happened to my niece in her 2003 Honda Civic. She complained the A/C no longer worked.
When I pulled the cabin air filter I think it had been there for 10 years it was so nasty with a science project growing on top. Nothing could get through it.