392 HVAC / This Working Correctly?

[MerlinsGarage]

Hey Guys, appologies if this is a known issue.
We live in the northeast. It's been a little chilly lately (20s F) and I cannnot figure out how to get HOT AIR out of the registers..?
This is our 6th Jeep from CJ to Wrangler JK and now JL. In every single previous Jeep the heater could literally cook you in the cockpit.
So, I turn both Driv and Pass heat settings all the way to "High" and put in recirc mode. System is in "Auto". The air temp coming out of the registers actually feels cool. I drove for 20 minutes and it did not get any warmer. Fan works fine. Defroster doesn't get hot either....? It's like a house with a heat pump, it gets the job done, but you never really feel warm.
What am I missing. I read the owners manual......duh. I don't get it.
Could really use your help since it is going to get substantially colder in the coming days.

Thanks for your help fellow Jeepers!!!

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[Dyolfknip74]

Hey Guys, appologies if this is a known issue.
We live in the northeast. It's been a little chilly lately (20s F) and I cannnot figure out how to get HOT AIR out of the registers..?
This is our 6th Jeep from CJ to Wrangler JK and now JL. In every single previous Jeep the heater could literally cook you in the cockpit.
So, I turn both Driv and Pass heat settings all the way to "High" and put in recirc mode. System is in "Auto". The air temp coming out of the registers actually feels cool. I drove for 20 minutes and it did not get any warmer. Fan works fine. Defroster doesn't get hot either....? It's like a house with a heat pump, it get the job done, but you never feel really warm.
What am I missing. I read the owners manual......duh. I don't get it.
Could really use your help since it is going to get substancially colder in the coming days.

Thanks for your help fellow Jeepers!!!

You're doing everything correctly. Something isn't right. I literally cannot hold my hand in front of the vents when in high.

 

[MerlinsGarage]

You're doing everything correctly. Something isn't right. I literally cannot hold my hand in front of the vents when in high.

Thank you Sir!!! That is encredibly helpful!!!!!
Kind regards and Happy Holidays,

Bret.

 

[multicam]

What happens when you take it out of “Auto” mode?

 

[MerlinsGarage]

What happens when you take it out of “Auto” mode?

Great question.
Manual operation (auto off) works the same a auto.

Thanks again,

Bret.

 

[2nd 392]

Would be way too simple, but have you checked for a kinked or mashed heater hose? Or a valve at their connections? Have been a victim of mechanics for both. ?

 

[Left Field]

The air temp coming out of the registers actually feels cool. I drove for 20 minutes and it did not get any warmer...
Thanks for your help fellow Jeepers!!!

Another bonehead check - looking at your coolant temperature (off-road pages or scroll through dash pages). Should be right around 200F normal operating temp. Stuck open thermostat would result in low temp and low heat output.

Also verify coolant reservoir level; improbable but an easy look.

LF

 

[MerlinsGarage]

I want to thank all the folks here for the great information and suggestions.
I checked everything I could under the hood without removing parts and found nothing glaring. Engine temp steady at ~190*. Jeep is still under warranty but wanted to see if it was something simple.
Never bought a new car that didn't have heat............
Happy Holidays to the Jeep community!!!

I'll post what happens..........
Kind regards,
Bret.

 

[RAMSTEEL]

Someone else recently had the same issue and it was a kinked heater hose coming into the firewall. Best of luck with the dealership, should be easy fix.

 

[76_iron]

I don't have any further suggestions on your JL heat, but I question your memory if you say your CJ would cook you out of the cab.

 

[MerlinsGarage]

I don't have any further suggestions on your JL heat, but I question your memory if you say your CJ would cook you out of the cab.

I had 2 CJs. CJ5 & CJ7. Both 258/6. And yes the heaters worked great. Even with just soft tops it would roast your feet.

 

[MerlinsGarage]

Someone else recently had the same issue and it was a kinked heater hose coming into the firewall. Best of luck with the dealership, should be easy fix.

You sir nailed it. Really appreciate the help.
Had a chance to crawl onto the back of the engine and look down at the heater hose mess. Unreal how Jeep thought this was engineered properly. There are at least 2 hoses kinked. Both restricted at least 50%. I tried to straighten them with little success.
From the pic you can see the kinked hoses at center-2 o'clock and the second @ 3 min-7 o'clock. The second one I was able to open up slightly but the first just bloodied my hands on the clamps.
Calling the dealership today.
Happy New Years, Jeep dudes and dudettes. You folks are the best!!!!!

Kind regards,
Bret.

 

[Xcoaste]

I will add that when I’m auto mode it seems like the air flows from the footwells. If you take it off auto, you can select where you want the air to flow from.
I notice a significant difference when I go to manual and and select air flow from the top forward vents. This is the only way passengers feel anything from the rear vents. I too miss the simplicity of a YJ or TJ heater!

 

[MerlinsGarage]

I will add that when I’m auto mode it seems like the air flows from the footwells. If you take it off auto, you can select where you want the air to flow from.
I notice a significant difference when I go to manual and and select air flow from the top forward vents. This is the only way passengers feel anything from the rear vents. I too miss the simplicity of a YJ or TJ heater!

100% agree. When it comes to HVAC simple is better.

 

[RAMSTEEL]

You sir nailed it. Really appreciate the help.
Had a chance to crawl onto the back of the engine and look down at the heater hose mess. Unreal how Jeep thought this was engineered properly. There are at least 2 hoses kinked. Both restricted at least 50%. I tried to straighten them with little success.
From the pic you can see the kinked hoses at center-2 o'clock and the second @ 3 min-7 o'clock. The second one I was able to open up slightly but the first just bloodied my hands on the clamps.
Calling the dealership today.
Happy New Years, Jeep dudes and dudettes. You folks are the best!!!!!

Kind regards,
Bret.

Awesome, glad it was something simple and the dealership will square you away. The forum is just a great resource.

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