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Weird ac and heating issue

3075 Views 17 Replies 5 Participants Last post by  basscatt
So I'm getting air out of the floor vents only. Nothing out of the dash vents or the top defrost. Driver side blows hot no matter if I have the temp hot or cold. I'm moving the passenger side actuator manually to hot or cold. I'm quite sure the actuator there is bad. So since theres only air out of the floor and no temp control on either sides, is that a bad actuator and module?

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Neither the modes or temp controls are working.
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So I'm getting air out of the floor vents only. Nothing out of the dash vents or the top defrost. Driver side blows hot no matter if I have the temp hot or cold. I'm moving the passenger side actuator manually to hot or cold. I'm quite sure the actuator there is bad. So since theres only air out of the floor and no temp control on either sides, is that a bad actuator and module?

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Neither the modes or temp controls are working.
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normally I would say check for codes -
because ALL hvac actuators are monitored -
those faulty ones should set a code -

but - knowing all the problems you've had with this car -
the problem might be caused by a stuck side-view mirror motor -
basscatt said:
--------------------------------- normally I would say check for codes - because ALL hvac actuators are monitored - those faulty ones should set a code - but - knowing all the problems you've had with this car - the problem might be caused by a stuck side-view mirror motor -
I hear you. It's crazy how many current codes there are, but no hvac actuator door codes. If there's no air coming out of the vents, would that be a vacuum leak or maybe a module??

I even found a small vacuum line that was broken earlier today. The previous owners really drove it into the ground. I'll get her all figured out :)
I hear you. It's crazy how many current codes there are, but no hvac actuator door codes. If there's no air coming out of the vents, would that be a vacuum leak or maybe a module??

I even found a small vacuum line that was broken earlier today. The previous owners really drove it into the ground. I'll get her all figured out :)
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If there's no air coming out of the vents,
would that be a vacuum leak or maybe a module??

no vacuum anywhere in the hvac system -
your Seville is all electronic -

here is the problem - as I see it -
when the system fails -
the MODE should go to the DEFAULT vent setting -
which is defrost and floor - yours doesn't do this -

could be this - could be that - could be the other thing -

with the TECH2 tool - it's a simple procedure to force/test ALL the actuators -
and pinpoint the problem -

without it - you are stuck guessing/replacing parts -

with that said - climate control modules are really cheap on ebay -

here is one for $15 including shipping -
http://www.ebay.com/itm/00-04-CADIL...001|Model:Seville&hash=item51b8fbde78&vxp=mtr

true - it is worn - and doesn't look pretty -
at this point - you just need to get it working -
and it can save a lot of time testing -
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basscatt said:
================================ If there's no air coming out of the vents, would that be a vacuum leak or maybe a module?? no vacuum anywhere in the hvac system - your Seville is all electronic - here is the problem - as I see it - when the system fails - the MODE should go to the DEFAULT vent setting - which is defrost and floor - yours doesn't do this - could be this - could be that - could be the other thing - with the TECH2 tool - it's a simple procedure to force/test ALL the actuators - and pinpoint the problem - without it - you are stuck guessing/replacing parts - with that said - climate control modules are really cheap on ebay - here is one for $15 including shipping - http://www.ebay.com/itm/00-04-CADILLAC-SEVILLE-CLIMATE-CONTROL-TEMPERATURE-UNIT-A-C-OEM-01-02-03-S604-/350995865208?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2001|Model%3ASeville&hash=item51b8fbde78&vxp=mtr true - it is worn - and doesn't look pretty - at this point - you just need to get it working - and it can save a lot of time testing -
I managed to keep my parts car yet for another day. I'll try and tackle that this morning before it goes. I remember seeing one screw holding it in at the bottom behind the ashtray on the console. I'll test it tho first before I pull it. Thanks for the advice. Might take a shot at the secondary air pump as well. I've never heard a Northstar run the way this does at idle. It runs fine then idles up and down. I hear a constant hissing sound near the manifold and my gut tells me there's a decent size vacuum leak somewhere.

Whatever I figure out today, I'll post. Thanks!
here is the problem - as I see it -
when the system fails -
the MODE should go to the DEFAULT vent setting -
which is defrost and floor - yours doesn't do this -
This is true with the old vacuum operated systems, but I'm not sure that the electronic are the same or even CAN default to defrost with a failed actuator.

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I've never heard a Northstar run the way this does at idle. It runs fine then idles up and down. I hear a constant hissing sound near the manifold and my gut tells me there's a decent size vacuum leak somewhere.
Yup, sounds like a vacuum leak. Check the plenum duct.
Ranger said:
This is true with the old vacuum operated systems, but I'm not sure that the electronic are the same or even CAN default to defrost with a failed actuator. ---------- Yup, sounds like a vacuum leak. Check the plenum duct.
If I turn the the door, it goes from cold to hot...but turning the door does nothing for the modes. I guess I'll give the electronics a shot.
Removed the air mod, put in a different one and still the same issue. Does the passenger side actuator control the heat and cold air mix as well as the modes- floor, defrost, vent etc...??
Removed the air mod, put in a different one and still the same issue. Does the passenger side actuator control the heat and cold air mix as well as the modes- floor, defrost, vent etc...??
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the MODE door actuator controls the MODE -

the #2 - passenger side - MIX door actuator -
allows the passenger to adjust the temp about 5* -
up or down - compared to the main - #1 - drivers side setting -
basscatt said:
======================== the MODE door actuator controls the MODE - the #2 - passenger side - MIX door actuator - allows the passenger to adjust the temp about 5* - up or down - compared to the main - #1 - drivers side setting -
Could it be a faulty mode door? Do you know where it's located?
Temp control and mode control are two different actuators.

I believe #46 is the mode control actuator and #44 is the passenger side temp actuator (if I remember correctly).

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Ranger said:
Temp control and mode control are two different actuators. I believe #46 is the mode control actuator and #44 is the passenger side temp actuator (if I remember correctly).
Thanks for the diagram Rang. Looks like it's just left of the center dash vents. Right underneath the dash pad?

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Ranger said:
This is true with the old vacuum operated systems, but I'm not sure that the electronic are the same or even CAN default to defrost with a failed actuator. ---------- Yup, sounds like a vacuum leak. Check the plenum duct.
So I couldn't see any visible cracks by the plenum and the codes are different from what my red STS was showing when IT had a bad plenum. BUT, I sprayed a little carb cleaner around it, and it sucked it right in and noticeably changed the way it ran. Tomorrow I'll take her apart to get a closer look. I'll let you know what I find out. Thanks for the tip!
Thanks for the diagram Rang. Looks like it's just left of the center dash vents. Right underneath the dash pad?
Yeah, that's about right. Here's a better over all view. You can still see the two left side actuators in the lower left view.

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Ranger said:
Yeah, that's about right. Here's a better over all view. You can still see the two left side actuators in the lower left view.
This diagram is for a 2000 STS? I'm looking for the two actuators on the left side of the vents but don't see any. Looks like in the diagram they would be behind and to the right of the info and on buttons....

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Ranger said:
Yeah, that's about right. Here's a better over all view. You can still see the two left side actuators in the lower left view.
Found it. Buried behind the radio inside the dash. Yikes!!

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Ranger said:
Temp control and mode control are two different actuators. I believe #46 is the mode control actuator and #44 is the passenger side temp actuator (if I remember correctly).
I believe I just pulled "46". Has an S labeled on it.
And whomever designed #40, should be taken out to the "back forty" and be shot. Lol! Just removed those filters on the SLS, rediculous set up. They're not going back in.
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centaur said:
And whomever designed #40, should be taken out to the "back forty" and be shot. Lol! Just removed those filters on the SLS, rediculous set up. They're not going back in.
Lol. Is that the dreaded cabin filter I keep hearing about?

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Does anyone know if actuators from the same years Deville will go in a Seville?
Can't help with the actuators. But yes, that's the cabin air filter.
Lol. Is that the dreaded cabin filter I keep hearing about?

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Does anyone know if actuators from the same years Deville will go in a Seville?
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Does anyone know
yes -
if actuators from the same years Deville will go in a Seville?
no -

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the parts you need are -

MODE door actuator = ACDELCO 1572631 -

#1 - driver side mix door actuator = ACDELCO 1572972 -

#2 - passenger side mix door actuator - ACDELCO 1572971 -
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