You are here:

Cadillac Repair/Hot air passenger cold air driverside

Advertisement

Expert: - 10/28/2011


Question
Hi, I have a 93 cadillac deville when i put it into heat mode on defrost it comes out warm on the passenger side but cold on the drive rside. the car does not overheat. would appreciate any help i can get. thank you for your time

Answer
Hello,

It sounds to me as if you have one of two problems. I would be checking all the vacuum lines under the dash for a restriction of a leak. The vacuum lines control the ventilation doors.
If vacuum likes appear to be OK, I would be looking at the A?C heater control.
Go for the lines first and check the mode doors.

It is one of these issues. The mode doors control where the ventilation goes. For checking them, you can go out and buy a cheap vacuum pump at the parts store. You need to go under the dash to see these mode doors. You apply the pump to the doors and you will see as to how it will direct the air. If you find that it now directs air to the left side by doing this, you have a vacuum line issue. The doors for the direction of the air are located under the passenger side and middle.

You could also take the chance of getting a used A/C heater control for $25-$50 bucks and try that. I am not a guy who recommends changing parts on a guess, however these A/C heater controls are known to fail and that may be your problem. At least I eliminated your problem down to 2 things. Hope it helps. Let me know.

Good Luck



I am now allowed to accept donations for my volunteer work after answering 10,000 questions being on this site. If my answer helps you and you feel compelled, you can donate by going to this link. It is not required, but it would be nice.



https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=HG2FU7R37AKNG

http://www.autotheftexpert.com  

Cadillac Repair

All Answers

Answers by Expert:

Ask Experts

Volunteer

Rob Painter

Expertise

Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?

Experience

Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

©2012 About.com, a part of The New York Times Company. All rights reserved.