A/C blows hot air when stopped. Fan clutch?? But wait...

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elexwiz

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2015 Ram 1500 Tradesman 5.7. I have the typical 'hot air from the A/C after when stopped' problem. I've replaced fan clutches on previous trucks for the same issue, but the difference now is the fan clutch itself. The fan clutch on these trucks are thermal clutches that should not engage until the engine gets hot enough. If that is the case, the fan will not be engaged on initial cold start, and the fan will be fairly easy to spin by hand when the engine is cold and stopped. The specs on these clutches say the fan will spin at 20-30% of shaft speed when disengaged. Is that still enough air flow for the A/C to work correctly when stopped at idle? Or am I looking at a different A/C problem? Thank you for your time.
 

62Blazer

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Typically the cooling fans are triggered on when the AC is turned on regardless of the engine temp. If the truck it sitting at idle with the AC off and the engine cooling fan not on, I would fully expect the cooling fan to come on when you turn the AC on. While it's not unusual for the AC to not feel quite as cool when the truck is setting still, it should still feel cool. That is simply because there is more air being pushed through the radiator with the truck cruising down the road at 55 mph versus what the fan pushes through it while sitting at a stop light.
 
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elexwiz

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Well... today I learned that my truck has TWO cooling fans... In my defense, I've only had it since March. I've been under the hood plenty of times, but the fan shroud is so close to the engine that you cannot see the electric fan. Didn't even know it was there! Thank you all very much for your replies!
 

18CrewDually

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Well... today I learned that my truck has TWO cooling fans... In my defense, I've only had it since March. I've been under the hood plenty of times, but the fan shroud is so close to the engine that you cannot see the electric fan. Didn't even know it was there! Thank you all very much for your replies!

The fan is also controlled by a relay so make sure you're getting power at the fan before you call the fan bad. Could be a simple relay.
 
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elexwiz

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Thank you all. Surprisingly, the fan was disconnected! I do not know why. :shrug:I found the fan plug just sitting in the shroud, and the vehicle-side plug stuffed near the back of the headlight. :oops: I connected the two and attached the plug to the shroud where it is supposed to go. Works like a champ! I also went through the engine bay looking for other orphan plugs... Now, if I could get my transmission issue fixed... https://www.ramforum.com/threads/transmission-frustration-after-repair.211079/
 

EdGs

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Thank you all. Surprisingly, the fan was disconnected! I do not know why. :shrug:I found the fan plug just sitting in the shroud, and the vehicle-side plug stuffed near the back of the headlight. :oops: I connected the two and attached the plug to the shroud where it is supposed to go. Works like a champ! I also went through the engine bay looking for other orphan plugs... Now, if I could get my transmission issue fixed... https://www.ramforum.com/threads/transmission-frustration-after-repair.211079/
Excellent! Love it when it's an easy fix.
 

Tominator223

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Glad ya found the problem. I’d now be asking myself who last had access to that part of my truck.
 

18CrewDually

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Glad ya found the problem. I’d now be asking myself who last had access to that part of my truck.

He's the recently new owner.
First thing that comes to mind is it was involved in a front end collision and the body shop that repaired it didn't plug things back in. A Carfax report MAY show that but no guarantee that it was reported, if that's the case.
 
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