ac/heater blower motor will not shut off completely

[myeaglescout]

Is it normal for you not to be able to shut off the blower motor completely? If I hit the button to slow it down below the lowest setting, the display goes dark as if it is turning everything off, but then it powers back up on low. System working fine otherwise as far as I can tell. Out of curiosity, I pulled the resistor assembly that's in front of the blower unit, and it has been replaced previously.

[Qsilver7]

Originally Posted by myeaglescout

...If I hit the button to slow it down below the lowest setting, the display goes dark as if it is turning everything off, but then it powers back up on low. ...

Need more details about the bolded text in your quote above. When is it powering back up? When you restart the vehicle? Or does it come back on regardless if the vehicle is running or not?

The IHKA (auto-climate system) is designed to turn back on at the lowest setting when it has been shut down completely. If you return to the car BEFORE it goes into SLEEP mode (approx 16 minutes)...then the system will stay shut down. But if you've shut the IHKA off...and then return to the car after 16 minutes...the system will start on the lowest setting...which then allows you to only have to press the button ONCE if you still want the system off.

[myeaglescout]

Thx for the reply, Q. Whether the car is running or not, if I push the left arrow button while it in the lowest blower setting, it immediately goes dark and then comes back on as soon as I push the left arrow on the blower control. In less than a second it comes on back in low. Mainly, I notice it when I'm turning the key on to the run position to use my scan tool. I can hear the blower running on low and it's draining the battery, so I try to turn it off, but it comes right back on. I don't sit around with the key in position usually, so it isn't really an issue. Mostly just curiosity.

I figure it just might be designed that way (like chevy started to do back in the 80's sometime), but it isn't addressed in my manual as far as I can see.

I have noticed that sometimes when I get into the car and start it, the blower is actually about midway to high..and I never have it there when I shut it down. Usually, it's on low or close to it. I have not thought to check to see if it's more or less than 16 min since I last was in the car, but I'll make a note to see if that makes any difference going forward. It does go into sleep mode as designed at the 16min mark, I do know that.

[andrewwynn]

As mentioned it's normal to come back on the lowest setting after power interrupt so it could be possible the scan tool is sending a signal on the buss that the HVAC interprets that way (as in how the air bag light comes on when I scan the air bag module).

Does it do this when your scan tool is not connected, say engine running etc. Sorry if I missed that above.

[myeaglescout]

yes, it does it running or not. I just checked it again to see about the sleep mode making a difference. if I start it up after it has gone to sleep, it actually turns the blower on one hash mark short of full speed even though it was on low when I shut her off. It might be because I have the temp set to 60degrees, but I'll have to change that next time and see if it makes a difference. (Don't laugh at me, I'm in Florida, and it's hot here on and off until Feb)

I also shut her off after doing the above test (and not waiting for her to go to sleep) and when I restarted, the blower was still set to the lowest setting. temp was still set to 60 as before.

[myeaglescout]

I just tried another test, and it does matter what temp you leave it set at. If I adjust the temp to match ambient (or close to it), if I get in and wake it from sleep, it starts the blower near the middle of the speed range.

I noticed that the button in the lower left corner of the climate control panel marked "AUTO" doesn't really seem to be a button like the 3 above it (they all push in and the led on them lights up when pushed in). Is the AUTO one supposed to be a button that moves in and out? Mine is in a permanent IN state, but the button can be wiggled a bit, so I was just wondering if it was stuck. The light on it stays lit always unless one of the 3 above it are activated. I think it goes out if MAX is pushed, but I'll have to check that when I get back in.

[andrewwynn]

Your auto button is broken. That will definitely cause problems. My scanner will report the state of the buttons as well as engage them if they are broken.

"Press the auto button".

The car is usually smart enough to ignore a stuck button but when that happens anything goes.

[HotWheelsRedline]

Perhaps replace the Final Stage Unit.