2005 1500 dual control HVAC 98,000 miles the fan blows at various speedsm but A/C isn't cold & heat isn't hot

[jjbendo]

2005 1500 dual control HVAC 98,000 miles

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I bought this in early April 2023. It was impressively clean inside and out. It's actually a Suburban. I thought I did a great job checking everything before I bought it, but I missed some important things. During my inspection the weather was very mild, there was no need to use the A/C or the heat. After purchasing it the weather got warm outside, I went to use the A/C, it didn't work. I checked under the hood, the clutch for the A/C did not engage. Simple enough I thought, it just must need more R-134. I added some and brought the pressure up to 32 PSI, within the green range. The clutch did not engage, I thought it should have. So, I started thinking. Then I realized I never checked the heat, so I tried it. It was only luke warm. So, I turned all the way up to 90, still luke warm.

I've been working on my cars and family and friend's cars for 30+ years and have had great successes.

But in this case, I need some help.

Pls let me know what you think.

John

 

[Doubeleive]

2005 1500 dual control HVAC 98,000 miles

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I bought this in early April 2023. It was impressively clean inside and out. It's actually a Suburban. I thought I did a great job checking everything before I bought it, but I missed some important things. During my inspection the weather was very mild, there was no need to use the A/C or the heat. After purchasing it the weather got warm outside, I went to use the A/C, it didn't work. I checked under the hood, the clutch for the A/C did not engage. Simple enough I thought, it just must need more R-134. I added some and brought the pressure up to 32 PSI, within the green range. The clutch did not engage, I thought it should have. So, I started thinking. Then I realized I never checked the heat, so I tried it. It was only luke warm. So, I turned all the way up to 90, still luke warm.

I've been working on my cars and family and friend's cars for 30+ years and have had great successes.

But in this case, I need some help.

Pls let me know what you think.

John

well sounds like a couple different issue's
1. the Ac should pretty much never get "low" unless there is a leak, maybe after many many years even then it "leaked" out somewhere.
2. the blend door/actuator under the glove box area could be stuck or non functional
if you refilled it there could be other issue's with the ac pump/system if it is not kicking on, this is seperate from the hot/cold problem inside the two issue's are unrelated
you can remove the kick panel under the glove box and you will then be able to visually see if the hot/cold blend actuator is moving or not and proceed from there, it's not uncommon for the actuator to fail. a couple bolts and a small hit to the wallet and that is usually resolved. the part under the hood takes a bit more troubleshooting.

 

[OR VietVet]

Welcome to the forum.

First thing that concerns me is the pressure of the a/c. The pressure should not be 32 psi. Even at static pressure, clutch not engaged, the pressure should be close to approximately 85 psi if you are at 80 degrees. You need hoses attached to both high and low side and see if the pressures are equal. If you added just one "suicide can" with the single hose, that is not gonna be dependable to gauge the problem with an a/c system.

Hopefully a moderator will move this thread to the correct section.

 

[jjbendo]

Thanks - Doubleeive & OR VietVet,
1. I will explore the hot/cold blend actuator.
2. I will borrow a friend's A/C gauge set and check the pressures.
3. What is the best way to hot wire the A/C clutch just to make sure it is working?

OR VietVet -
How much of a difference did the Hellwig Performance Sway Bars and Black Bear Performance Traditional Tune make?

 

[Marky Dissod]

If for any reason you suspect the coolant is 'old' or worse, the heatercore(s) tend(s) to collect contaminants before the radiator. If so, hopefully you can backflush the heatercore(s) before they need replacing.

Then again, maybe it's just the blend doors.

 

[OR VietVet]

Thanks - Doubleeive & OR VietVet,
1. I will explore the hot/cold blend actuator.
2. I will borrow a friend's A/C gauge set and check the pressures.
3. What is the best way to hot wire the A/C clutch just to make sure it is working?

OR VietVet -
How much of a difference did the Hellwig Performance Sway Bars and Black Bear Performance Traditional Tune make?

For future reference, add the @ mark in front of anybody's screen name and that member will get a notification you referenced them and want their comment.

To do a quick check, you can pull the connector at the accumulator low pressure switch and cross the two wire connection and the clutch should engage. When you turn the a/c system on, you should have power at the a/c compressor plug in as well. You really need to get gauges on the high and low side and report back here what pressures you see. If the a/c is off, the pressures should be very close to the same and the ambient temp will change the readings. It is almost 1 psi for every degree of temp. Up or down.

The Hellwig Performance Sway Bar kits, front and rear, made all the difference in the world. I can 'flat track" thru a high speed curve and there is little to no body lean.

The BBP traditional tune gives me more power and better response and maintains the mpg as long as I keep my foot out of it. The transmission shifts are firmer. I have a Corvette servo and I feel the difference in the shift much more than I did after the servo install.