99-newer Silverado p/u's and 2001-newer Sub/Tahoe

JLeosnow · June 27, 2005

Has anyone figured out exactly which part has failed when you cant get the temperature in the cabin to go back to cold when turning the temp. control knob from cool to hot and then back to cool? I believe this seems to be a very common problem in the 99-newer Silverado p/u's and 2001-newer Suburban & Tahoe models..... We have a 2001 Suburban 4X4 LT that this situation happens sporadically but would like to get the problem resolved. Any info would be greatly appreciated. Please inform.

Thanks,

-John

Shawn T · June 27, 2005

Damper motor. It happened twice on my 99. The first time it happened like you have mentioned, sporatically. The second time it just stuck on the hot side. The part seemed to be fairly cheap but it takes a little bit of labor to get in there. It was under warranty so I was not too concerned.

JLeosnow · June 27, 2005

Damper motor. It happened twice on my 99. The first time it happened like you have mentioned, sporatically. The second time it just stuck on the hot side. The part seemed to be fairly cheap but it takes a little bit of labor to get in there. It was under warranty so I was not too concerned.

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sstimothy,

Thanks for the responce. I have a couple more questions for you on this if you don't mind.....

Is this the exact name of the part(what I would ask for at the dealership) and exactly where is it located? I'm assuming on the heater core box on the passengers side of the interior....??

Thanks,

-John

carguru · June 27, 2005

Ask for a blend actuator.

Shawn T · June 28, 2005

sstimothy,
Thanks for the responce. I have a couple more questions for you on this if you don't mind.....

Is this the exact name of the part(what I would ask for at the dealership) and exactly where is it located? I'm assuming on the heater core box on the passengers side of the interior....??

Thanks,

-John

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I am not posative of the exact location, mine was done at the dealership under warranty. I would imagine it is where you think it is. I have heard of people taking the cover off of the duct work under there and looking right at it. The screw that is on top of the "hump" is kind of hard to get to. I changed the cabin filter on my 99 a couple of times. I just can't quite remember what was all under there. As far as terminology, I call it the "HVAC damper motor". "Blend Actuator" sounds appropriate also. They will know exactly what you are talking about at the parts desk, it is a fairly common problem.

JLeosnow · June 29, 2005

Thanks for the info sstimothy & carguru....much appreciated!!

-John

carguru · June 29, 2005

I am working from memory, but there should be 2 actuators. One is on the bottom of the plenum near the center of the dash, the other is up behind the dash on the driver's side. I believe that the one on the bottom of the plenum is the one that controls the blend (the one you are having problems with). The other is the one that diverts the airflow (defrost, panel, floor, etc.). Hope that helps.

Markeaux · June 29, 2005

The exact name as shown on the GM parts screen is the "temperature valve bottom actuator" PN 52474810 ... My local Chev parts dept said I had to bring the bad part in before they would sell me a replacment so I got mine from GM Parts Direct - after describing the part they replied with an email showing a pic of the parts blowup of that part of the system so it was easy to make sure that was the correct part ... I was able to swap mine out myself, but it was a bit difficult due to tight working space ... All I can remember is that I dropped the hush panel and the part was easily seen toward the bottom on passenger side - The Helms manual detailed the R&R (I strongly suggest getting a full set of those manuals, even if just to keep mechanics honest

JLeosnow · June 29, 2005

The exact name as shown on the GM parts screen is the "temperature valve bottom actuator" PN 52474810 ... My local Chev parts dept said I had to bring the bad part in before they would sell me a replacment so I got mine from GM Parts Direct - after describing the part they replied with an email showing a pic of the parts blowup of that part of the system so it was easy to make sure that was the correct part ... I was able to swap mine out myself, but it was a bit difficult due to tight working space ... All I can remember is that I dropped the hush panel and the part was easily seen toward the bottom on passenger side - The Helms manual detailed the R&R (I strongly suggest getting a full set of those manuals, even if just to keep mechanics honest

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Thanks for the info Mark!! When you say you had to "drop the hush panel" I'm assuming you mean a panel on the heater core box located on the passenger side.....is this correct?

-John

Markeaux · June 30, 2005

Yeah the hush panel is the black cover over the bottom part of the passenger side IP - I guess it's called that because it reduces fan noise. It's held on by 1 or 2 trim bolts that need to be removed, but the other one way over by center hump only needs to be loosened (it's too hard to remove it). Then just pull the entire hush panel down and out of the way ... that's the same procedure to get to the 2 cabin filters.

JLeosnow · June 30, 2005

Yeah the hush panel is the black cover over the bottom part of the passenger side IP - I guess it's called that because it reduces fan noise. It's held on by 1 or 2 trim bolts that need to be removed, but the other one way over by center hump only needs to be loosened (it's too hard to remove it). Then just pull the entire hush panel down and out of the way ... that's the same procedure to get to the 2 cabin filters.

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Mark,

Thanks again for the detailed information.

-John

rjirvine · June 30, 2005

How much was the part? Can you disassemlbe it and lube it or anything?

JLeosnow · June 30, 2005

How much was the part? Can you disassemlbe it and lube it or anything?

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rjirvine,

MSRP on the part is $52.62..... Sorry but I don't know the answer to your 2nd question.

-John

jchilling · November 3, 2007

Old thread. Sorry from this newbie. I have the exact problem as described in this thread. I went out and bought the actuator and installed it in my 2001 Tahoe and the problem is still there. Now I can turn the temp knob to about 75% hot and back to cool and it will work but if I go to 100% hot, it will not return to cool unless I park the truck for an hour (off) or I pull the fuses in the dash AND the engine compartment.