Last post on Sep 30, 2013 at 7:06 PM
You are in the Maintenance & Repair
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Heating / Cooling
#787 of 839 Re: bronco a/c [buck96]
Aug 09, 2009 (4:16 pm)
You should check all the rubber lines and the tank which serves as a reservoir for vacuum and check the one-way valve that is in the system somewhere so that the intake manifold vacuum can suck air out of the system controlling the heater unit, but when vacuum in the motor drops under high load or flooring it, the higher pressure air can't flow into the heater system.
Aug 09, 2009 (4:19 pm)
I am having a problem with my A/C, I have read you post & I am hoping you might have an idea of whats going on,,
I have a Chevy Venture 2000
The van has 3 center of dash vents...
Left and center now give warmish air...
The furthest to the right gives cold air???
What could be causing the problem...
Is there a blend door ? Part of AC not cooling?
We have been all over looking for some answers but with no luck at all. Even dealer ships!! If you have any info on this please share!!! I have to get this fix & get back on the road for work, kids, etc.... living in Florida A/C is a must have!
Thank You for your time!
#789 of 839 Re: AC/Heating [brandiwine06]
Aug 09, 2009 (9:17 pm)
Have an airconditioner shop check your freon level.
#790 of 839 Re: AC/Heating [brandiwine06]
Aug 10, 2009 (4:43 am)
I posted yesterday but something happened and the post is not here!
On some H-bodies (2000+ Bonneville, LeSabre) people have noted that the passenger side will be cooling fine and the driver side gets warmer air. The owners have looked for phsical causes in the HVAC unit but others found that a low charge results in the freon's cooling ability being used on the side of the evaporator where it enters and the air from that side goes to the passenger side of the car, while the freon isn't as cold as it expands on the rest of the evaporator where air goes to the driver. It still cools but it doesn't feel nearly as cold as the passenger air, probably partly due to less humidity removal along with a slightly higher temp.
Your HVAC unit may not be the same but that should have been the first thing a dealer checked and made sure the freon was fully charged.
Good luck finding the cause and the fix.
#791 of 839 Re: AC/Heating [brandiwine06]
Aug 12, 2009 (12:55 pm)
"...Left and center now give warmish air...Is there a blend door..."
I seem to remember that on GM vans the blend doors are controlled by vacume. Depending on engine load the vacume in those doors can fall and redirect air flow. Thus if you are going up a steep hill you might have the air switch from face level to foot level without changing the settings.
Check your lines for leaks.
#792 of 839 2001 Tahoe heater that blows lukewarm air
Dec 30, 2009 (6:35 pm)
So far,the mechanics have changed the thermostat, flushed the coolant 3/4 times, raised the front of the vehicle to remove air bubbles, replaced the fan clutch, replaced the temp actuator, replaced the inside filters, replaced the control switch panel, blew out the ducts, made sure that the coolant level was high enough, and who knows what else and still lukewarm air comes out of all positions. Help!!
#793 of 839 Re: 2001 Tahoe heater that blows lukewarm air [wolferman1]
Dec 31, 2009 (6:23 am)
Since they replaced the actuator motor for the blend door, I assume, assume they checked the movement of that blend door to be sure it was able to move completely to the setting sending all air through the heater core?
Then it's down to how hot is the heater core? Are hoses to the heater core after driving 15 or more minutes so the engine temp is full hot both very hot even after the blower motor has been on HIGH for several minutes with the motor idling? That would indicate full flow through the core.
Otherwise, my next step would be a heater core flush using only its hoses to gently, gently move air and water through it backwards and forwards. If the DexCool or other coolant weren't changed in 9 years there may be some goop clogging the tiny water channels.
Good luck. It's down to scientific analysis of symptoms.
#794 of 839 Re: 2001 Tahoe heater that blows lukewarm air [imidazol97]
Dec 31, 2009 (2:22 pm)
The coolant has been changed at least once a year for the last five years. The blend door is working like it should. The coolant hoses are hot going in and coming out.The blower is also blowing a lot of air. Help again..
#795 of 839 Re: 2001 Tahoe heater that blows lukewarm air [wolferman1]
Dec 31, 2009 (2:43 pm)
I suspect you are not getting air flow thru the heating core, some sort of air blockage.....or the damper that brings in outside air is stuck open, bringing in too much cold air.
#796 of 839 Re: 2001 Tahoe heater that blows lukewarm air [wolferman1]
Dec 31, 2009 (3:09 pm)
flushed the coolant 3/4 times
Did they do a back flush? That would usually clear any blockage in the block and heater area. If they did, it makes no sense that they do it 3 to 4 times which is already suspect. Also raising the front end of the vehicle to remove air bubbles sounds like something click and clack would do.
One thing you could do now is to check the overflow tank and make sure it is at least filled to the cold line. If it is then check the radiator to see if it is topped off. Please do this when the motor is cold.
Other than that you may want to change mechanics.