Tactical_Geek

So when it's around 80 and below my AC seems to work just fine. It feels like it's blowing cold air from the vents... but as soon as it's above 85 or so it's just hot inside no matter what I do. Like I said, the compressor is running, the fan is cycling like it should, and the air feels cold but the cabin just stays hot.

So is it a Jeep thing because of the lack of insulation or is there a problem with my AC?

corupt1

My first guess would be that you are low on freon. Have a check ran on your AC system and they should be able to tell if you are low. Keep in mind your AC system is closed, so if it is low, there is a leak. so that freon will leak out until you fix the leak.

ronjenx

With the controls set as follows, this is what you should see at the center panel outlet:

• Engine at idle and operating temperature
• Doors or windows open
• Transmission in Park or Neutral with parking brake set (depending on application)
• A/C-heater controls set to Recirculation mode (max-A/C), full cool, panel mode, high blower and with A/C compressor engaged.

Ambient temp------------ Center panel discharge air temp
70°F ----------------------- 42°F to 59°F
80°F ----------------------- 45°F to 64°F
90°F----------------------- 48°F to 69°F
100°F---------------------- 52°F to 72°F
110°F---------------------- 56°F to 75°F

Tactical_Geek

Rednroll

I'm assuming that's from the service manual? They sure do give themselves a pretty wide range of air temp. A 20 deg swing seems pretty big.

I use Eric The Car Guy's method which is similar to the specs Ron posted. You want a 30-40deg temp difference from the outside ambient temperature blowing from your vents, and if you get that then you're good.
This video will also provide more details on how to properly take the measurement which oddly enough is different from the service manual.

ronjenx

The data in my post above are from the JK service manual.

There are some fundamental differences in the settings between the video and the JK service manual.

When checking a JK, the settings from the service manual are the proper ones to follow.

Rednroll

The measurement method differences I noticed.
Service Manual vs ETCG
- Recirculate On vs OFF
- Blower HIGH vs LOW
- Windows Open vs Closed

What I noticed when measuring mine previously. With the blowers on High, it will provide a higher temp reading than low.
Recirculate On will provide a lower temp reading since it's taking in cooler air from the interior. However, the SM also mentions to have the windows open, which to me kind of negates the purpose of turning the recirculate on. At the end of the day, it likely balances out, where you would see similar temp readings but if that's the method the SM calls out, then that's the one you would want to use if you need to prove to a dealership something isn't right. So thanks for posting!

jedg

It's all relative. The heat exchanger (that's what an AC system is) can only remove a certain number of BTUs of heat. So the important part is to replicate what the SM says because that's the reference points they've chosen. Otherwise you won't know if your system is working optimally.

FWIW, the output temperature should be lower when the blower is on low (for a given ambient temperature and all other variables equal) because the air is in the heat exchanger longer so more heat is removed. Which goes back to why it's significant to use the SM conditions so that you're comparing apples to apples.