Passenger Side Heating Not Working (3 Viewers)

[Justbuckstuff]

Longtime lurker but first post:

My passenger side heating doesn't work but my drivers side works great.

-Replaced the thermostat and radiator last fall.
-Timing belt and water pump this year
-Radiator topped off recently
-Engine temp is stable
-Had issue with condenser fan not working so only hot air in October but that fixed itself somehow.
-If vents are open on passenger side, driver side is toasty and passenger is cold. When vents are closed on passenger side, driver side is less warm

Two possibilities I’ve come up with are the heater core needs to be flushed and the blend door could be stuck.

I’d love any advice or experience anyone can share regarding this issue or heater core flushing in general as I want to try this before I dismantle the dash to play with the blend door. Passengers might just have to suck it up at that point.

Thanks,

Buck

 

[drowzyGX]

Passenger side blend mix motors are easy enough to check.

Remove the glovebox and trim around it. You’ve got 2 servos along the center console in the passenger side footwell. You can see them clearly. Cycle the AC through hot and cold, see if they move. There’s another one between the blower motor and passenger side fender area. Blower motor has to come out to check it.

not sure which is the mix / blend servo. I replaced all 3 in mine last year. All failed within 6 months of each other.

 

[Justbuckstuff]

Passenger side blend mix motors are easy enough to check.

Remove the glovebox and trim around it. You’ve got 2 servos along the center console in the passenger side footwell. You can see them clearly. Cycle the AC through hot and cold, see if they move. There’s another one between the blower motor and passenger side fender area. Blower motor has to come out to check it.

not sure which is the mix / blend servo. I replaced all 3 in mine last year. All failed within 6 months of each other.

Okay guess im dismantling the passenger side tonight. Seems like a common problem.
Ive been reading about pressing some buttons and having the car spit out codes for ac system failures. Did you try that? Im curious to see if it works and tells me if/which servo has failed.

 

[drowzyGX]

Okay guess im dismantling the passenger side tonight. Seems like a common problem.
Ive been reading about pressing some buttons and having the car spit out codes for ac system failures. Did you try that? Im curious to see if it works and tells me if/which servo has failed.

I’ve done the self test. Doesn’t always show up on there. Worth a shot before pulling apart the passenger side. Think you hold the auto and recirc buttons then turn the ignition to “ON”, and info will flash across the hvac lcd panel.

 

[Justbuckstuff]

The floor vent servo and the circulate servo are working nicely with their doors. The mix servo works but I cant see the door to see if thats actually moving. Is it possible to get to the door itself (or at least view it) or do you have to tear the whole thing apart?

PSA for people reading this in 5-10 years: floor vent has a release on the back. Dont just rip it off bc you'll break it...

 

[ad27326]

Bringing this back! So, purchased my 04 GX last week, noticed this morning as it was a little cool outside and the wife needed some heat, that when I turned dual "ON" to "HIGH" that driver side was warm-not hot-passenger side cold. Turned off dual, same result, turned A/C on and both sides equally cold, turned heat back "ON" to front defrost and the driver side half was warm, passenger side half cold. Also, earlier today I removed the Phoenix PX6 and reinstalled the factory unit as I was planning to sell and put funds towards a lift, etc. Once I had the factory unit installed, the "check the a/c " message appeared on the display therefore no heat or a/c working. I have read several threads both here and Club Lexus, sounds like a servo issue but why would I have a/c on both sides? Any input or ideas as far as what to check would be appreciated!!

 

[ad27326]

Nobody else has had or had this problem??

 

[drowzyGX]

Best bet is to hook yourself up to tech stream if you can. Another option is doing the ac diagnostic check. I’m not sure what you have to hit as far as buttons go to enter the diagnostic mode. There’s some sequence of buttons and (if you have nav) screen presses to activate it.

as to having ac AND a servo issue, that’s possible (I think). If the servo is dead on one side, the blend door can be stuck open or closed (or mostly open / mostly closed). This would lead to one temp working in that side but not the other temp. Basically it’s always getting a mix that’s mostly (or entirely) cold air.

 

[ad27326]

Best bet is to hook yourself up to tech stream if you can. Another option is doing the ac diagnostic check. I’m not sure what you have to hit as far as buttons go to enter the diagnostic mode. There’s some sequence of buttons and (if you have nav) screen presses to activate it.

as to having ac AND a servo issue, that’s possible (I think). If the servo is dead on one side, the blend door can be stuck open or closed (or mostly open / mostly closed). This would lead to one temp working in that side but not the other temp. Basically it’s always getting a mix that’s mostly (or entirely) cold air.

Thanks for the info, I will research the diagnostic mode and see what I can find.