A/C does not blow air cold until truck has warmed up

2004 CHEVROLET SILVERADO
210,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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SKYLARDOG123
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  • 4 POSTS
My truck doesn't blow cold when i first crank it, it has to reach operating temperature first (205°f) after that, it's ice cold. the compressor runs the whole time but it isn't blowing cold until it reaches temperature, any ideas?

New high and low pressure switch, new climate control switch, the condenser is clear of debris. Truck is equipped with electric fans that turn on at 185 degrees.
Aug 3, 2021 at 4:12 PM
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MASTER ASE TECH
  • ✓Experienced Mechanic
  • 82 POSTS
Hi, I'm Dan. If the compressor is running, then we want to feel the lines going into the evaporator core at the firewall to see if they are cold. Any chance of getting pressure readings on the system?
Also, when the truck is first started, does the mechanical fan make noise like it's working? Does it flow a lot of air when it's idling with the A/C on? There is a possibility that the mechanical clutch is not working.
I've attached a pinpoint test for checking the fan.

There is also the chance that the A/C system is low on refrigerant.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak
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Aug 4, 2021 at 4:44 AM
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SKYLARDOG123
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A/C lines are cold, just had system vacuumed and charged as well, i don't have a mechanical fan, i have electric fans that kick on at 185 and 195.
Aug 4, 2021 at 12:18 PM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Good afternoon,

Can you give us the high and low-side Freon pressure readings when the A/C system is running? We need to see that to be sure the pressures are correct.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Roy
Aug 6, 2021 at 6:28 AM
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SKYLARDOG123
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I'm not sure the exact number but i had my dad vacuum and charge it with 28.8 oz like Friday hoping to fix my issue and it did not.
Aug 6, 2021 at 6:53 AM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Okay, I need the high and low side readings as a start to determine the issue.

Please post them when you get them so I can help.

You can rent a set of gauges at a parts store or buy a cheap set.

Roy
Aug 6, 2021 at 7:03 AM
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