Main IndexAuto Repair Home Search Posts SEARCH
POSTS 		Who's Online WHO'S
ONLINE 		Log in LOG
IN




Automotive Repair
Car Troubleshooting Topics
  Car Troubleshooting
  Engine Troubleshooting
  Engine Fault Codes
  Electrical and Wiring
  Transmission Problems

Car Repair Topics
  Car Making Noises
  Car Stereo Repair
  Heating or AC Issues
  Motorcycles and ATVs
  Tricks of the Trade
  Truck Repair Advice

Site Options:   
  Login
  Sign up here!



Latest Forum Post
with_replies.gif image   1989 toyota pickup 3.0 crank no start
I have a 1989 toyota pickup 3.0 crank no...

with_replies.gif image   Strut spring orientation and strut mount tension nut
2017 Nissan rogue awd 2.5 L Put in Monro...

with_replies.gif image   Transmission stuck in part, I have tried everything
So I'm working on my elderly fathers 201...

with_replies.gif image   2017 dodge journey LED headlights on/off randomly
Year of vehicle 2017 Make of vehicle dod...

with_replies.gif image   Kia Soul starter replacement issues!
Okay so my car is a 2010 Kia soul 2.0 en...

hot_with_replies.gif image   Please Help - Knock sound & engine fail
Hi all, Hoping to get some insight and ...

with_replies.gif image   multiple warning lights
2013 GMC Terrain 130,000 miles 4 cylinde...

with_replies.gif image   03 alero no low speed blower
Good day everyone, I have a 2003 Olds a...

with_replies.gif image   04 Chevy 2500hd tail light issues
Help!!! I have changed my combo switch...

with_replies.gif image   1999 Grand Caravan Sport not starting.
Hi. I'm new here. I hope someone can hel...




A/C acting weird

Search for (search options)
 



chattylill
New User

Jul 10, 2011, 3:13 PM

Post #1 of 3 (1869 views)
A/C acting weird Sign In
1995
Chevy
g20
350
130K
k

I recently had a new transmission put in the van and when we got it back the a/c started to blow cold air through the vents properly when idle but when accelerating would blow cold air through the defrost and to the foot area of the dash. When it is in this mode it doesn't cool the van very well. When we tested the heat that doesn't seem to work at all. Also the rear blower though blowing air no longer blows cold air even when it is idle. I need some help! Thanks so much!


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jul 10, 2011, 3:34 PM

Post #2 of 3 (1864 views)
Re: A/C acting weird Sign In
 The mode selection is done through a series of air doors that are operated by vacuum. When there is either a partial or total loss of vacuum, the system will default to either defrost or on some vehicles, heat. Acceleration can also have an effect on the doors for the same reason.

Look under the hood for a small black plastic hose coming through the firewall. Follow it to the vacuum source looking for any breaks, cracks or leaks. Also follow any other lines that branch off because they may go to a vacuum reservoir (storage tank) and a leak there will cause the same problem. Using a vacuum gauge to determine if you have full vacuum at any given point is the best way to find it. You can cut into the line anywhere and splice it back together with a piece of vacuum hose. Find the broken line, you found your problem.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



chattylill
New User

Jul 10, 2011, 4:18 PM

Post #3 of 3 (1858 views)
Re: A/C acting weird Sign In
Thank you so much! We will look at that now! I'll let you know if we find anything there!





 
 
 






Search for (options) Privacy Sitemap