air conditioning works only when moving, otherwise hot air

davidg91 · **Joined:** Wed Apr 08, 2015 1:01 pm **Posts:** 33

Recently, I started hearing a louder engine/fan/? noise independent of engine speed when it's on.

Shortly after that, I observe the air conditioning works well only when moving, otherwise it just blows hot air.
Maybe the a/c fan in the engine bay isn't working? Any ideas?

flash7210 · **Posted:** Sun Aug 23, 2015 5:17 pm

Yup.
One or both of your cooling fans is not working.

davidg91 · **Joined:** Wed Apr 08, 2015 1:01 pm **Posts:** 33

Thanks. I just popped the hood and took off the cooling fan shroud. I saw the thin plastic condenser fan had broken off and split into 4 big pieces and several small ones. The fan motor does still work though. The shroud also had a 4" x 4" chunk taken off too. The shroud was tough to take out. It was about 2mm too deep to get past the engine fan. I had to twist the shroud a bit to get it out.

Now I need to shop for the shroud and fan blades and see if they are cheaper than getting the whole assembly.

My KJ has the factory towing package which I assume includes the heavy duty cooling.

Some sites like partsgeek list an A/C Condenser Fan Assembly and an Auxiliary Fan Assembly Dornan Dorman 621-017 as the same thing, but I have not seen just the blades yet.

davidg91 · **Joined:** Wed Apr 08, 2015 1:01 pm **Posts:** 33

I could find the shroud and motor separately but not the fan blades, so I ended up ordering the whole assembly. I'll keep the old working fan motor in case the new one dies in another 10 years.

I don't look forward to having to twist and force to get the new shroud in. I'm disappointed that the old shroud was 2-3 mm too deep to clear the engine fan. I'll either twist and bend the new one if needed or trim it to make it fit.

TwoBobsKJ · **Joined:** Fri May 11, 2012 8:03 pm **Posts:** 463

davidg91 wrote:

I could find the shroud and motor separately but not the fan blades, so I ended up ordering the whole assembly. I'll keep the old working fan motor in case the new one dies in another 10 years.

I don't look forward to having to twist and force to get the new shroud in. I'm disappointed that the old shroud was 2-3 mm too deep to clear the engine fan. I'll either twist and bend the new one if needed or trim it to make it fit.

Just trim about 3/4 of an inch off the bottom of the shroud just slightly wider than the mechanical fan. It's a common mod done to eliminate the need to remove the mechanical fan and clutch from the water pump every time you want to take out the shroud. You'll be able to slip the shroud passed the fan and into the slots at the bottom where the shroud tabs fit. Should be no more than a 15 minute install once you've trimmed the bottom of the shroud.

Bob

davidg91 · **Joined:** Wed Apr 08, 2015 1:01 pm **Posts:** 33

Trimming that 8" wide x 3/4" deep section at the bottom of the shroud made placement a very quick and easy thing.

The A/C works great again now at idle and when moving.

I noticed, and I don't know how long this has been going on but it started before that condenser fan broke, that when I use the a/c in fresh air mode I get much more air, 10x as much, than when I have it in recirculate mode. The air is cold in both cases, but regardless of the fan speed the fresh air mode pushes much more air and the recirculate mode pushes very little air.

Has anyone else seen this?

flash7210 · **Posted:** Sat Aug 29, 2015 7:39 pm

The inlet vent for recirc mode can get plugged up.
Its a pain to get to. Gotta remove the glove box.
Just use your hand to scrape the crud off the screen.

TwoBobsKJ · **Joined:** Fri May 11, 2012 8:03 pm **Posts:** 463

flash7210 wrote:

The inlet vent for recirc mode can get plugged up.
Its a pain to get to. Gotta remove the glove box.
Just use your hand to scrape the crud off the screen.

Agreed that the issue is the inlet - it gets clogged and prevents air from getting to the fan. The recirculate should actually give you MORE air so the 'filter' is definitely blocked.

Just open the glove box and slide the door to the side to remove it. Back in there a ways you'll see a bunch of dust (which is covering the inlet.) Wipe it off with your hand while holding a vacuum nozzle to it and you'll start to see a grill or grid. Clean it off good and then reverse the procedure. Turn on your air and notice the improved airflow in the recirculate mode :wink:

Bob

davidg91 · **Joined:** Wed Apr 08, 2015 1:01 pm **Posts:** 33

That was it. I removed the glove box and saw 10 years of dust on the inlet. The re circulate mode now works perfectly.

Arkie · **Posted:** Sun Aug 30, 2015 11:03 pm

That would a been a great place for one a them cabin air filters.

Bob

TwoBobsKJ · **Joined:** Fri May 11, 2012 8:03 pm **Posts:** 463

davidg91 wrote:

That was it. I removed the glove box and saw 10 years of dust on the inlet. The re circulate mode now works perfectly.

Glad to hear you have cooler A/C now thanks to working recirculate position. Now on to the next Jeep mod :SOMBRERO:

Bob

air conditioning works only when moving, otherwise hot air

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