A/C on "NORM" setting...no cold air with High Fan

[MSDGN]

I charged up my A/C (R12) and I think it's OK...on an 85 degree day high side pressure was 190 and low side was around 30...I used an A/C temp gauge in the vent...air coming out vents was 42-43 degrees...on the "MAX" A/C setting with fan on low...med...med-hi air stayed around 43 degrees...when I turn the fan to high the temps did go up to around 50 degrees but I think that's normal since the A/C in my truck did the same thing...the problem is when I use the "NORM" setting...with the fan on low or med the temps are 42-43...but I turn the fan to med-hi and the temps go up to around 60 degrees...the real problem is with the high fan setting...the air coming out the vents isn't cold...it isn't warm either...basically ambient temp...on my temp gauge the temp just kept going up until it hit 80 degrees...why is this only happening with med-hi and high fan using "NORM" setting...

 

[turbo nasty]

Did you replace reciever and pull vacum before charging. These cars are a fixed restrictor and refrigerant needs to be weighed in...how many cans or lbs did you put in?

Posted from the TurboBuick.Com mobile app

 

[MSDGN]

I just put about a can and a half in...didn't do anything else...so not replacing the receiver and not pulling vacuum would cause my problem?...why is the problem only on "NORM" setting with fan on med-hi or high?

 

[Nick Micale]

Scott, check your heater control valve to be sure it is in the off position.

Another possibility could be the blend door is not functioning properly since the NORM setting flows outside air instead of recirculating inside air in the MAX setting?

These 25+ year old vacuum controls AC are now being a more frequent problem on our cars.

 

[MSDGN]

Nick...I thought blend door might be the problem...not sure what you mean "check your heater control valve to be sure it is in the off position"...how do I check that?...also how do I check the blend door...do I have to remove the cowl cover under the hood?

 

[Nick Micale]

The heater control valve is spring loaded to the ON position, it needs vacuum to move and stay in the CLOSED position.

The blend door is also vacuum actuated and is under the dash.