salimshah

Any idea what this fuse controls... from the post it seems the blower motor is OK.

Salim

BlackRX300

Thanks for the detailed instructions on finding and removing the fuse#32, 15 amp. I already new where the fuse was located and asked if you new what the fuse did in relationship to the heater?

Please read all of my post.

Thanks

BlackRX300

As stated in my earlier post:

The coolant level is full.

Please read all of my post.

Thanks

Tammy

Pardon,
I did read your post and no, I do not have your year specific wiring diagram at my disposal ... No, I do not know what specific circuits this fuse supplies power to.

salimshah

BlackRX300:

Beleive me, we are all trying our best. Your problem has us stumped and it is all gratis.

Has any work been done on your vehicle?

Salim

BlackRX300

Don't get me wrong, I think this is GREAT FORUM! I have found a lot of help on here before.

But when I post my problem and someone does not even bother to read the entire post, then starts telling me check things that I have already said I have checked, it's frustrating.

Asking what a fuse does in relationship to the heater and getting detailed instructions on where the fuse is located and how to remove it is just damn stupid.

I've worked on my own cars for about 20 years and I have the Lexus manuals for my 2001 RX. I know where the fuses are located and how to remove one. I know how to turn the heat on and I know how to check the coolant level.

If I post that my heater does not put out warm air and I get a reply to turn the setting to "HOT" instead of 80, WOW, I should of thought of that on my own. 80 is the highest setting except for HOT. I guess maybe set at 80 would not produce warm air from the heater. That's like having to set the A/C to COLD, because 60 wil not blow cold air. HAaaaaaaaaaaaaaaaa

I do appreciate all of the suggestions given and I really do think there are very knowledgable people on this forum. Others must just like to see themselves type.

salimshah

I did some hunting...

BUT

Take it at its face value ...

There is a heater fuse and also a heater relay (some where behind the panels roughly in front of the driver's left knee (inside the cabin). I strongly feel (not a fact) that the fuse and the relay work to heat the mirror and have nothing to do with the cabin heat.


Back to your issue:

We are down to
1. Heated coolant not getting into heat exchanger
2. Some flap inside the heat exchanger not operating. [air flow ducts have been eliminated].

You can spot where the a/c refridgerant lines enter the fire wall (from the engine side). Right next to them are 2 coolant rubber hoses with spring clamps. With the engine hot, can you try to reach and feel the metal nipples. Both should be hot to touch.

Next thing would be to open up the heat exchanger. [A conclsuion you might have already reached].

I honestly think, at this time you have exhausted all possible suggestions from this forum. It just might be the time to pay the piper.

Salim

If wrong type of coolant was used in the past, you can get into corrosion problems and possibly blocked core in the heat exchanger. Lexus (Toyota) are very finiky when it gets to fluids.

BlackRX300

Well...I guess it's off to the dealer.

Lil4X

On behalf of our helpful DIY'ers, please don't be offended by some of their more "obvious" advice. We are a family here, but all of us come from different experience and backgrounds. For some of us, an oil change is a major project - others may not even know where the new oil goes. We're kind of a mixed family. For some of us, major mechanical repairs hold no terror - others peer under the hood only in frustration.

We have no idea where our correspondents lie along this continuum, so if we are sometimes a little simplistic in our responses it is probably for one of a handful of reasons:

1. We have no idea what your technical expertise might be, or what you might have already done to troubleshoot or repair your problem.
   
   
2. We are often unfamiliar with the special requirements of your application, your roads, and your climate – all of which may affect a diagnosis.
   
   
3. We have a large number of readers, many of whom may benefit by your experience, so if we back up a few paces and maybe retrace your steps, it’s not that we don’t think you’ve given it some thought, but that others in the same situation may not. Club Lexus has just slightly less than 50,000 registered members with about the same number of regular visitors who have not registered. It’s a big family, and we continue to grow.

To all of our correspondents, thanks for posting! It may perform not just a service for you, but a LOT of other people too . . . even when we make mistakes, we learn, and that serves others in the audience who might have a better approach and chime in.

Also, when our members FIND a solution, we ask that they report back to the committee. If your problem is solved, it helps guide others. If not, it may save a number of others from chasing down that same rabbit trail.

We try not to be too obtuse around here, but in the interest of serving the greater number of our members and guests, sometimes we have to conduct a remote diagnosis with a lot of people looking over our shoulders. That’s the purpose of our little community.

Hey, it’s a tough job, but somebody’s got to do it!

salimshah

One last item:

Does any one know how the cabin temprature setting works on heat?

Does it contol the blower speed only or it operates some valve or flaps. [alsalih mentioned a process to bypass the cabin thermostat .. but that bypasses the temprature sensor]

Salim.

justfixit

Sounds like you have a defective air mix servo.
Try this:
Key Off
Push AUTO button and RECIRC button at same time and continue to hold
Turn Key on
This enters diagnostic mode which will give A/C system codes
Code 21 will be normal if no light is shining on Solar sensor on dash
Any other codes displayed will be abnormal condition.
Servos have malfunction codes. Post your results

justfixit

Heater fuse controls blower motor

BlackRX300

Right on target. Wish I had heard from you earlier. You were right about the servo.

Lexus replaced a dead air mix servo. I was told the part was over $200 and labor, again over $200 @2 hours.

$200.00 for a servo, gee wiz, I'm in the wrong business.

Total to have heat this winter $476.51. WOW!!

salimshah

Bad ac in summer would set you back $1200 minimum.

These beasts are expensive, when it comes to repair.

Thanks for posting what actually went wrong.


Salim

BlackRX300

Anyone have an idea how much an "Air Mix Servo" cost?
Any parts source to check this price would be appreciated.
Online site or source with 1-800 number.

Thanks again,