QuestionQUESTION: Recently only 1/2 (driver side) of the windshield will defrost. Also heat will only come from the passenger side vents. Driver side remains cold although passenger gets warm. Plenty of heat so it is not the heater core and AC works fine. Could it be the distribution valve under the dash on the passenger side? Had also been making an odd squeaking noise from that area too although it was hard to tell exactly where it came from. Either that or one of the diverter valves?
Thanks for any input
Greg
ANSWER: Hello Greg,
Make, model, year would help. The A/C is a separate system than heat. As for the distribution and temp on the other side, that sounds like a mode door or two not functioning, usually created by a vacuum problem. Most mode doors are controlled by vacuum. Door(s) could be binding or vacuum line pinched.
You would hav to get under the dash, find the mode doors and apply a vacuum pump to them o see which ones are functioning. Cut off vacuum or a binding door would explain the noise you are hearing as well.
http://www.autotheftexpert.com
---------- FOLLOW-UP ----------
QUESTION: Thanks Rob,
Sorry about not identifying the car! It is a 1997 Cadillac Eldorado ETC. Pulled the distribution valve at the passenger side and it seems fine. Air flow to various places seems OK and it is just the heating that seems not to get to the right place. Is there a specific diverter that controls hot/cold?
AnswerHi,
http://www.gmpartseast.com/cadillac/components/1997-eldorado-base-model_ks-air-d
As I stated before, you will need to get up under the dash and use a hand held vacuum pump on the mode door giving you your noise and lack of warm air in that location.
The only diverter I am aware of is at the control. Everything else is controlled by vacuum lines going to specific doors. A pinched line under the dash could also give you an issue.
Good luck.
http://www.autotheftexpert.com
