AC not cold during idle but cold all other times

[Heath Trost]

last year I got my heater core and evap core replaced due to a heater core issue... I think I had this issue all the time but I really notice my AC is not cold when idle the truck... as soon as I get higher RPM's and actually start moving the air gets cold.

any ideas what causes this?

I have an AC charge kit, I need to check the low pressure to see if it is low but I wouldn't think it would be low as it got recharged last year with the work I had done on it.

 

[Wahrsuul]

Sounds like the electric fan isn't working. Once air gets flowing when moving or the engine fan gets enough going then it works. At idel, the electric fan would be doing the job.

 

[RamDiver]

Check this thread. Same Ram year and the same fault.

The AC condenser fan and Wahrsuul called it.

2013 ram 1500 hemi AC problems

When i travel on Highway or streets AC works great. When I come to a stop the AC starts to warm down and blows warm air. I start to move again and the ac will get cold. I have an clutch fan for the motor. Is there a fan for the AC condenser? is it hard to replace if bad. If I Hot wire the AC...

www.ramforum.com

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[Heath Trost]

Thanks RamDiver... didn't find this with my search... I have the same exactly problem. I just confirmed the fan is not turning when AC is turned on... that is my problem. thanks

 

[RamDiver]

Thanks RamDiver... didn't find this with my search... I have the same exactly problem. I just confirmed the fan is not turning when AC is turned on... that is my problem. thanks

You're most welcome and please keep us posted on future developments.

There are lots of members that can help point you in the right direction if required.

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[turkeybird56]

You're most welcome and please keep us posted on future developments.

There are lots of members that can help point you in the right direction if required.

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DITTO..!!

 

[Wahrsuul]

HA!, got one right! Better mark that on the calendar...

Might just be the fan relay, the fans themselves usually last.

 

[jerbo1978]

last year I got my heater core and evap core replaced due to a heater core issue... I think I had this issue all the time but I really notice my AC is not cold when idle the truck... as soon as I get higher RPM's and actually start moving the air gets cold.

any ideas what causes this?

I have an AC charge kit, I need to check the low pressure to see if it is low but I wouldn't think it would be low as it got recharged last year with the work I had done on it.

I have a 2012 ram quad cab with the 4.7 engine...I have same problem..Electric condenser fan isn't coming on when I turn ac on...I keep getting engine light with code p0481...fan circuit ll malfunction..fan will work when bypassed

 

[jerbo1978]

Thanks RamDiver... didn't find this with my search... I have the same exact problem. I just confirmed the fan is not turning when AC is turned on... that is my problem. thanks

I'm having the same issue with my 2012 Ram.
Electric fan wont come on when i turn AC on.
Did you figure out what was wrong ?

 

[Wahrsuul]

First thing to check is the fuse and relay. Those are usually the culprits.

 

[RamDiver]

Thanks RamDiver... didn't find this with my search... I have the same exactly problem. I just confirmed the fan is not turning when AC is turned on... that is my problem. thanks

Hi Heath Trost

As Wahrsuul mentioned, confirm the fuses are good. Verify that the connector at the fan is seated, then remove and inspect contacts inside the connector for corrosion. Re-attach the connector and press it firmly into place.

AFAIK, the primary fuse for the AC condenser fan is F03 and the AC clutch signal is F62.

If those fuses are not blown, relays K01 or K02 could have failed. I'd try to hotwire the fan to see if it works before bypassing the relays. Another member with more experience with those specific relays may choose to bypass them first.

Fuse Box Diagram Dodge/Ram Pickup 1500/2500/3500 2009-2018

Fuse box diagram (location and assignment of electrical fuses) for Dodge Ram / Ram Truck Pickup 1500/2500/3500 (2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018).

fuse-box.info

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[jerbo1978]

Hi Heath Trost

As Wahrsuul mentioned, confirm the fuses are good. Verify that the connector at the fan is seated, then remove and inspect contacts inside the connector for corrosion. Re-attach the connector and press it firmly into place.

AFAIK, the primary fuse for the AC condenser fan is F03 and the AC clutch signal is F62.

If those fuses are not blown, relays K01 or K02 could have failed. I'd try to hotwire the fan to see if it works before bypassing the relays. Another member with more experience with those specific relays may choose to bypass them first.

View attachment 521382

Fuse Box Diagram Dodge/Ram Pickup 1500/2500/3500 2009-2018

Fuse box diagram (location and assignment of electrical fuses) for Dodge Ram / Ram Truck Pickup 1500/2500/3500 (2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018).

fuse-box.info

.

I have a 2012 Ram Quad cab with a 4.7..my fusebox is different than that one pictured

 

[RamDiver]

I have a 2012 Ram Quad cab with a 4.7..my fusebox is different than that one pictured

Hi jerbo1978

Please start a new thread and post all of you observations and tests you've tried in that new thread.

I'll investigate your vehicle particulars when I'm next at my PC, I'm using a phone now.
Thanks

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[GTyankee]

May i suggest that you keep a assortment of Fuses & a
Fuse checker



I also suggest that you press down on each fuse, to see if they might be loosened up

 

[RamDiver]

I also suggest that you press down on each fuse, to see if they might be loosened up

That's always a great idea for chasing any electrical gremlins, especially the intermittent faults.

My heated steering wheel used to shutoff on its own and I haven't had the problem once since pushing in all the fuses.

Many seemed to be a couple of millimeters from fully seated.

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[pacofortacos]

I don't think the fan comes on instantly when you turn the AC on, it comes on when the hi side pressure gets high enough.
I can check mine tomorrow but unless I am mixing my vehicles up I am pretty sure that's how my ram is.

Also, if your truck has shutters, it is possible for the shutters to be closed when the AC is on - this usually just gives you less cold air for a period though (until the parameters to open the shutters are met).

 

[PaleFlyer]

I don't think the fan comes on instantly when you turn the AC on, it comes on when the hi side pressure gets high enough.
I can check mine tomorrow but unless I am mixing my vehicles up I am pretty sure that's how my ram is.

Also, if your truck has shutters, it is possible for the shutters to be closed when the AC is on - this usually just gives you less cold air for a period though (until the parameters to open the shutters are met).

My '18 is starting to do the same thing as OP's truck. My Rebel doesn't have shutters. (Factory delete on the Rebel's apparently.) Was starting to think I needed to have the refrigerant swapped/replaced/refilled, but now wondering if maybe my fan has shat the bed. My commute is ~30 miles each way, and the AC still sucks at idle even after 20+ minutes of highway driving. It's Antarctic cold at highway speeds, or even just once I stabilize over ~35MPH for a minute, which makes sense if the eFan isn't doing its job, as that would be enough time for the truck to "blow out" the heat from the engine just sitting in the carolina heat, probably even with NO fans. Guess it's probably a good thing I haven't gotten around to doing the cFan delete yet.

 

[jerbo1978]

My '18 is starting to do the same thing as OP's truck. My Rebel doesn't have shutters. (Factory delete on the Rebel's apparently.) Was starting to think I needed to have the refrigerant swapped/replaced/refilled, but now wondering if maybe my fan has shat the bed. My commute is ~30 miles each way, and the AC still sucks at idle even after 20+ minutes of highway driving. It's Antarctic cold at highway speeds, or even just once I stabilize over ~35MPH for a minute, which makes sense if the eFan isn't doing its job, as that would be enough time for the truck to "blow out" the heat from the engine just sitting in the carolina heat, probably even with NO fans. Guess it's probably a good thing I haven't gotten around to doing the cFan delete yet.

The electric fan doesn't come on at all..
If I unplug it from the connector and jump it with battery,it works...

 

[Jeepwalker]

Besides the fan it could be slightly low on refrigerant, or even a slight amount of moisture in the system. See how it performes once the fan is operating properly. Hopefully that'll do the trick. Did you put any thermometers in the dash vents going down the road to measure the output temp?

 

[BuschLatte420]

I feel as if my 2022 classic as could be better both on the temperature side and blower motor power side, I understand it’s a crew cab but my old tahoes ac kicks this things ass, on a 80-85F day I have to have max ac on coldest setting for awhile before cold enough to turn it down. Temp out the vents is 45F give or take, this is with putting a thermometer in the vent same as the dealer would probably do, so not going to bother taking it in. Falls in the good area via post I saw floating around here