HVAC Erratic on LX470

[100OR470]

I own a 2005 Lx470. The HVAC is erratic: (1) passenger side gets cooler air from its vents than driver side [on cloudy days so sun not the cause]; (2) temp is sometimes very slow to respond to come up to set temp, and at other times the system overshoots the set temp significantly [i.e., significantly warm air continues to come out even when temp has reached set point, usually 68-70°F]

This is a new car to me, so I need basic help as to where to start, other than going to dealer. I have done multi-term searches, and haven't turned up anything resembling this problem. Please forgive if i missed the obvious or available!

 

[PADDO]

Search for a recent thread by Muddy Bean "climate control temp sensor' I think that might help, check your front floor vents haven't been covered over by the carpet and I'd also check your cabin air filters too. All easy stuff.

Sent from my iPhone using IH8MUD

 

[100OR470]

Paddo

Thanks. Seems like this could be my problem. Found the input 'grill', and then spent an hour trying to find a Factory Service Manual so I don't break plastic when trying to remove the panels. Got it and tomorrow I may have time to start disassembling things.

Thanks, John

 

[JETTIX2]

Post up your results

 

[100OR470]

I first removed the Lower Panel No.1 below the steering wheel. The 'aspirator' hose may or may not have been connected to the temp sensor module — I couldn't tell for sure, because the pull to get the panel off may have pulled the hose off too.

The temp sensor was really clean! Almost nothing on it — only a thin film of dust.

Decided to check the cabin air filters. Getting at them took a while longer, due to the tether-retractor on the glove box door. Filters were only slightly dirty, and there was a bit of dirt on the bottom of the filter compartment. Blew the filters out and vacuumed the filter box.

Will have to wait until I have a drive longer than around-town errands to tell if the heating is more even.

Overall, the first two owners drove in a lot cleaner territory than I tend to!