AC blows warm when stopped

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OR VietVet

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If the fan clutch is original, there is likely no way that it is functioning 100%. I would start planning on replacing that even if you need to add refrigerant. When you do get readings on the gauges, note them, the ambient temp at the time and whether the compressor clutch is cycling and what the gauge readings change to when this happens and then post that info here. You can also go to you tube and watch several videos about what to expect. I say watch several because they are not always the same.
 
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slypher25aussie

slypher25aussie

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If the fan clutch is original, there is likely no way that it is functioning 100%. I would start planning on replacing that even if you need to add refrigerant. When you do get readings on the gauges, note them, the ambient temp at the time and whether the compressor clutch is cycling and what the gauge readings change to when this happens and then post that info here. You can also go to you tube and watch several videos about what to expect. I say watch several because they are not always the same.

I'm not the original owner, so unsure of the fan clutch's life. It was well taken care of though. I'm already watching a bunch of videos, so I feel pretty confident checking the levels. Does anyone have a PSI chart for our trucks? Is the PSI the same whether you have the 5.3 or the 6.0?
 

91RS

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The fan clutch is easy to diagnose. On first start up, you should get a "jet roar" if the clutch is good. The other test can be a bit dangerous so proceed at your own risk, but you can use a screwdriver to hold the fan blade and have someone else start the engine. If you can hold the fan still (or rotate it backwards), the clutch is most definitely bad.
 

corvette744

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I replaced my fan clutch when i thought that was the problem nope.I had the ac checked all was perfect they said-but at idle it was alot warmer than when driving.I didnt like this as i left my dog in the car sometimes when i ran into store.I did notice that if i just held the idle a tiny bit higher with my foot it got colder.So i got out my diablo sport tuner went in to modify factory tune raised idle 100-150 rpm and wolla all fixed.Ice cold air at idle.More air flow at idle is what you need.Unless your gonna add electric fans you might have to do this.
 
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OR VietVet

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I recommend that you watch some videos about good and bad fan clutches and how it effects the a/c system when engine is hot and at a stop. The a/c system gauges will climb if the engine cooling system is not functioning properly. I believe you have a fan clutch problem but I also always want to attach gauges to verify the system operation.
 

Mooseman93

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I'm not the original owner, so unsure of the fan clutch's life. It was well taken care of though. I'm already watching a bunch of videos, so I feel pretty confident checking the levels. Does anyone have a PSI chart for our trucks? Is the PSI the same whether you have the 5.3 or the 6.0?
I agree that suspect #1 is the fan clutch, but another cheap and easy one is the tensioner pulley. If its spring is weakening, it's possible that it's slipping at lower rpms. A compressor that is in the early stages of failure can really wear on those things too.
 
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slypher25aussie

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I agree that suspect #1 is the fan clutch, but another cheap and easy one is the tensioner pulley. If its spring is weakening, it's possible that it's slipping at lower rpms. A compressor that is in the early stages of failure can really wear on those things too.

I replaced the belt and tensioner recently. Going to try hooking up my AC gauges first, then I’ll try the clutch.
 

mattt

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Another option is to change your fan style to the 05-06 electric fans. They drop right in place of the stock shroud and the factory wire harness and controller for them can be retrofitted to your 03. After that all it takes is an ECM tuner to turn on the fan control in your factory ECM. If you're looking for those parts, I'm your huckleberry and in Orange County as well.
 
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slypher25aussie

slypher25aussie

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Another option is to change your fan style to the 05-06 electric fans. They drop right in place of the stock shroud and the factory wire harness and controller for them can be retrofitted to your 03. After that all it takes is an ECM tuner to turn on the fan control in your factory ECM. If you're looking for those parts, I'm your huckleberry and in Orange County as well.

Oh sweet! Are you able to do the tune? I always wanted to pull those fans at the junkyard but I didn’t know anyone that could activate them.
 

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