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99 STS blows hot on dirver side while air is on


Captain Rob

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After searching the forums I found a thread exactly related to my problem

link from 2009

I've responded to that thread with no luck of a response, I'm posting it here because we are going through another week of 90+ temps here in MI.

Before you respond, remember, this a dual climate control AC, which only applies to the 1998 and upward models.

Question, can someone explain in detail or post a pic of the procedures from the manual on how to change the driver side actuator?

From what i understand its under the dash and not above the kick panel? How do I remove the dash panel, and will it be easily noticeable?

Any help will be much appreciated.

Captain Rob (Rather be on my boat but must fix the Caddy)

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When a HVAC door and the door actuator motor are out of sync., a Diagnostic Trouble Code will eventually be set. Knowing the DTC will eliminate guess work.

Here's here's how to display the codes on your dash:

http://www.caddyinfo.com/readingcodes.html

You will be most interested in "B" for Body codes.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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These are the three codes:

DTC B1310 Ambient Air Temperature Sensor Failure

This "could be" a factor in your HVAC problem. If your dash OUTSIDE TEMP display is not reasonably close to actual ambient air temperature, I would suggest you replace the sensor. Located on the hood latch support bracket.

DTC C1712 LF Damper Actuator Open CKT

DTC C1717 RF Damper Actuator Open CKT

Nothing to do with HVAC. But you might have non-electronic aftermarket struts installed. Should also result in a SERVICE SUSPENSION SYS message on the dash.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Yeah, if the ambient temperature sensor does not know what the temperature is, it doesn't know whether to heat or cool, much less how much. Fix that first.

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The outside air temperature stopped working after I just had the head gaskets replaced and time serted.

So the problem was happening before that. But I will replace anyway. Can you give me an idea of cost? I do have the driver side actuator already, so if its relatively simple, I can replace. Just need input.

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I replaced my heater core last spring, and took some pictures while doing it. You can find the description of it if you go to post #9 in this thread:

http://caddyinfo.ipbhost.com/index.php?showtopic=28646&st=0&p=165660entry165660

or go directly to the pictures (only) here:

http://picasaweb.google.se/112056579231243335600/97DeVilleHeaterCoreReplacement?authkey=Gv1sRgCN3bjeDPsrS8rgE&feat=directlink

I guess much of it may not apply on your car, but in some of the figures the heater box and the control rods are visible, so that you can get an idea of what they look like.

I have put one more picture up for you, which shows the little doors that are actuated by the control rods (the picture is from inside the heater box, after it was opened):

http://picasaweb.google.se/112056579231243335600/97DeVilleAirDoorsInsideOfHeaterCore?authkey=Gv1sRgCMvxpN_p9aubmwE&feat=directlink

All the pictures are from my '97 DeVille, which does have dual climate control.

Hope it helps!

Jonas

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I would not replace the door actuator motor before the ambient temp. sensor is working properly.

If the door remains in the wrong position after you replace the ambient temp. sensor, there is a little trick that works for me.

Sometimes the problem is simply a matter of the motor being out of sync. with the temperature controller. Very slowly, one degree at a time, cycle the commanded temperature through the entire range several times.

And yes, the actuator motor can fail.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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I would not replace the door actuator motor before the ambient temp. sensor is working properly.

If the door remains in the wrong position after you replace the ambient temp. sensor, there is a little trick that works for me.

Sometimes the problem is simply a matter of the motor being out of sync. with the temperature controller. Very slowly, one degree at a time, cycle the commanded temperature through the entire range several times.

And yes, the actuator motor can fail.

Aren't those actuated by vacuum lines? I think they are in my car, and in that case there could be a vacuum leak causing the problem.

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Aren't those actuated by vacuum lines? I think they are in my car, and in that case there could be a vacuum leak causing the problem.

HVAC doors on 1998+ Sevilles (and 2000+ Devilles) are controlled by electric motors.

And that is only the tip of the iceberg of differences.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Aren't those actuated by vacuum lines? I think they are in my car, and in that case there could be a vacuum leak causing the problem.

HVAC doors on 1998+ Sevilles (and 2000+ Devilles) are controlled by electric motors.

And that is only the tip of the iceberg of differences.

Aha, you learn something new every day :). Guess my pictures are not all that relevant then, oh well... Good luck anyway, Captain Rob

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The outside air temperature stopped working after I just had the head gaskets replaced and time serted.

So the problem was happening before that. But I will replace anyway. Can you give me an idea of cost? I do have the driver side actuator already, so if its relatively simple, I can replace. Just need input.

Maybe the sensor is unplugged? It is near the center of the radiator support. If the sensor is bad, it is about $25.00 at the dealer.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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  • 3 weeks later...

Is the air from the passenger side ducts cool? If so, I would think the system is low on refrigerant.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Yes, the passenger side is nice and cool, the refrigerant was replaced when I did the alternator/generator a few months back.

I have a replacement driver side actuator, is it under the dash or above the kick panel on a 99 STS w/dual climate control?

Just looking for the procedure on replacing. Thanks in advanced.

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I'm not sure of the placement on the '98+ Sevilles. The earlier styles had one under the passenger kick panel and the other one was accessed by removing the glove box.

With the A/C on, feel the evaporator inlet and outlet pipes - they should be the same temperature. If the outlet is warmer than the inlet, the system is low on refrigerant. If they are both approximately the same temperature, then the issue is an actuator.

It may be possible the actuator is not calibrated correctly or it has died. Someone with a '98+ service manual should be able to tell you where the driver's side actuator is and the procedure for calibrating the replacement.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Even if you had Volume 1 of 3, you still would not know for sure where the door and actuator are located. There is no illustration for the driver air mix actuator in my '98 Service Manual.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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  • 3 weeks later...

Ranger, that did help. I found the actuator, I had to removed the kick panel on the driver side and it seemed to be working properly. I could hear it working as I changed temps.

Anything else I should trouble shoot for?

Did you check the items that I outlined in my earlier post? If so, what were the results?

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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