Geesh, now another problem......heat/air/defrost does not vent right

[UKcat]

We first noticed this problem when I turned the defroster on; now it is the same with the heat and air. I checked the codes and got IPM 1344. According to the list, this is HTR/DEF/AC Door Movement Fault. We figured that something was not opening or closing to control the air coming out of the vents, but did not know what.

O.K., you diagnostic people; please tell me what this is and how do we fix it????

Is it coincidental that this started happening after he replaced our battery cable and did we tear something else up?????

[JimD]

Check that code for a typo....

Should be in the form of one letter followed by four numbers.

[Cadillac Jim]

B1344 HeaterDefrost/AC Door Movement Fault

There is a set of solenoids that operate a valve body for vacuum lines that operates the vacuum servos for the HVAC. It's located under the dash near the glove compartment on Eldorados and Sevilles up through 1998, and quite possibly on your 1998 STS. The vacuum goes through that body to the emergence brake release, so you can do a quick check by putting the emergency brake on in Park and seeing if it releases when you put the transmission in Drive. If so, then the problem is probably in the vacuum lines between this manifold and the servos, or a sticking door.

[UKcat]

Thanks, Jim, for your quick reply. We will check this out tomorrow. I just sort of feel like we knocked or pulled something loose when we replaced the battery cable at the point where it goes through the firewall. I hope it is something that simple!!

[JimD]

You will not find any vacuum operated servos in a '98 to '04 Seville chassis.

All the HVAC door actuators are DC electric motors, and they are inter-changeable (as in plug-in compatible). Makes for easy access to spare parts for test purposes.

[Logan]

Did the the new battery cable fix the below 35 degree starting issue?

[UKcat]

Did the the new battery cable fix the below 35 degree starting issue?

Yes, it did; however, what we found with the cable was a little disturbing to me. We peeled the rubber off the cable, looking for corrosion that was indicated to me from other posters to be the problem. What we found was a burnt place in the cable about 4 inches long, at the point where it went through the firewall. It was very dark and brittle. I posted some pictures of it in my thread about it last week, I think. I guess this had weakened the cable and was causing it not to have enough power to start on cold mornings.

Beats me!!!

[UKcat]

You will not find any vacuum operated servos in a '98 to '04 Seville chassis.

All the HVAC door actuators are DC electric motors, and they are inter-changeable (as in plug-in compatible). Makes for easy access to spare parts for test purposes.

Thanks for the info. Now, where do we find these motors??? I assume that they are located under the dash area, but I do not know for sure. Also, are these available at local parts houses or do I have to get one from a dealer???

[JimD]

Thanks for the info. Now, where do we find these motors??? I assume that they are located under the dash area, but I do not know for sure.

Yes, there are four door actuators and they are all located under the dash, more or less. The one you are concerned with is called "mode actuator" in the Service Manual and it is buried deep under the dash on the firewall. Removal instructions (Service Manual) for the dash involves 40 steps over two pages.

You really do not want to R&R that actuator motor. It's worth a try to get the system to synchronize and start flying right. Try toggling slowly through the various mode selections. Pause at each selection for at least 30 seconds. Repeat seveal times.

Failing that, take it to a Cadillac dealer and have them try to synchronize the actuators with a Tech II.

Also, are these available at local parts houses or do I have to get one from a dealer???

If it comes to replacing the actuator motor, I would use only OEM parts.

[Ranger]

I am a little confused UKcat. What exactly are your symptoms?

[UKcat]

I am a little confused UKcat. What exactly are your symptoms?

We first noticed that when I turned the defroster on, it was operating but the air was not coming out of the vents near the windshield. Last week on a cool morning I noticed that it did not seem like the heater was working very well. Again, it was operating but it did not seem like the vents were working properly. Yesterday, it was pretty stuffy here; when I left from work, I lowered the temp. so that the air would come on. Again, it did operate, but the air did not come out of the vents; it was coming out under the dash, near my feet.

I don't know if we loosened a connection somewhere when we replaced the cable, or if this has happened since that time.