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Unread 02-17-2012, 03:55 PM   #1
OTownDaddy
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Wj 2 A/C vents throughput crappy

So, the weather has been fantastic recently, so I haven't been using the A/C. Yesterday, I decided to turn it on (it hit 82) and noticed that 2 of the vents weren't blowing at full power. Attached pic has them outlined in red. The other 3 have acceptable flow, although they too don't feel like the one in green (it has by far the most power.

Any ideas as to what might be the issue and a possible fix?

dash.jpg  
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Unread 02-17-2012, 07:25 PM   #2
Cobra Jeep
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I have noticed my 99 does that. Exactly the same as you have pictured. The red ones do not flow very much, and the green one does, so does the one on the left of the steering wheel. Havent thought to check the one on the far right.
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Unread 02-17-2012, 07:37 PM   #3
Gran_Paradiso
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Quote:
Originally Posted by Cobra Jeep
I have noticed my 99 does that. Exactly the same as you have pictured. The red ones do not flow very much, and the green one does, so does the one on the left of the steering wheel. Havent thought to check the one on the far right.
I do know the two middle ones come from one outlet. I had to add some foam to seal the channel connecting to the hvac unit. It leaked air before it came out of the vents.
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Unread 02-17-2012, 07:59 PM   #4
gtg413i
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i notice the same thing on mine. I'd just chalk it up to another WJ thing / design flaw / quirk / uniqueness / annoyance / $$ to fix. Maybe it has to do with the heater treater I did. Did you do that to yours.

Sorry for the pessemistic attitude, just got back from trying to figure out why the WJ ran out of coolant and not too happy with why they require some special HOAT coolant. I think I solved the coolant leak due to upper radiator hose clamp being loose.
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Unread 02-17-2012, 09:02 PM   #5
99WJdan
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Same here on my 99'. Also the ones on the floor blow poorly as well.
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Unread 02-17-2012, 09:34 PM   #6
OTownDaddy
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Well, at least it's not a unique issue

Quote:
Originally Posted by Gran_Paradiso View Post
I do know the two middle ones come from one outlet. I had to add some foam to seal the channel connecting to the hvac unit. It leaked air before it came out of the vents.
Do you have to remove the dash to check out what's up or can you just remove the plate around the stereo?
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Unread 02-17-2012, 09:40 PM   #7
Gran_Paradiso
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Quote:
Originally Posted by OTownDaddy View Post
Do you have to remove the dash to check out what's up or can you just remove the plate around the stereo?

I took the bezel trim or plate as you say and the stereo out. I bought some of that narrow foam weather strip at the hardware store and resealed the connection to the HVAC duct. My foam deteriorated and air diverted away from exiting the vents.
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Unread 04-19-2012, 04:15 PM   #8
OTownDaddy
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Reviving this as I'm thinking before it gets out of hand hot here in Orlando, I'll be needing to get this sorted. I think it needs a recharge, as it just doesn't blow as cold as expected. That's the easy part.

The 2 center vents come from the same place, seems odd that one blows like a madman and the other barely blows. Did a cursory check of the A/C path leading into the vent and all seems OK. Still wondering why one flow awesome and the other, well, blows (in a bad way).

Also, noticed the other day when I had the A/C on that when I sometimes accelerate hard, my A/C switches to come out of the defrost vents, then switches back to normal A/C vent flow. Is this a vacuum line (like the one under the battery tray) issue?
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Unread 04-19-2012, 05:01 PM   #9
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Quote:
Originally Posted by OTownDaddy
Reviving this as I'm thinking before it gets out of hand hot here in Orlando, I'll be needing to get this sorted. I think it needs a recharge, as it just doesn't blow as cold as expected. That's the easy part.

The 2 center vents come from the same place, seems odd that one blows like a madman and the other barely blows. Did a cursory check of the A/C path leading into the vent and all seems OK. Still wondering why one flow awesome and the other, well, blows (in a bad way).

Also, noticed the other day when I had the A/C on that when I sometimes accelerate hard, my A/C switches to come out of the defrost vents, then switches back to normal A/C vent flow. Is this a vacuum line (like the one under the battery tray) issue?
Before i fixed my blend doors i had the exact problem.Wasnt blowing cold on one side and vents were strong in the middle,weak on the sides.After the blend door fix my vents are balanced and blow hard out all of them.I dont understand how the blend doors affect velocity,but it did on mine.
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Unread 04-19-2012, 05:11 PM   #10
OTownDaddy
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I don't have dual climate...but I guess I still have a blend door of sorts, right? Diverts air to defrost, floor, etc? Wonder if that's the issue...
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Unread 04-19-2012, 05:24 PM   #11
billzcat1
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There's a mode door as well as a blend door in the MTC system. The blend door is responsible for the mix of hot and cold air and is electronic. The mode door changes the pathway through HVAC box determining which vents are blowing. This one is vacuum controlled. The blend door on MTC models doesn't have the same issue as the AZC models since it doesn't do the same calibration routine that breaks the blend door axles.

I'd say its probably an air leak in the system somewhere.
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Unread 04-19-2012, 05:25 PM   #12
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Check out this TSB: http://wjjeeps.com/tsb/tsb_wj_240799.pdf
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Unread 04-19-2012, 08:06 PM   #13
OTownDaddy
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Very interesting. Wonder if there is something at work that would make one center vent blow less than the other. Maybe they each have tubes that supply each of them? Time to check that FSM.

Now to track down vacuum lines...
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Unread 04-20-2012, 01:08 AM   #14
MoparMan1990
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I've had the same issue I never really bothered to mess with it because it blows fine on the drivers side
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Unread 04-20-2012, 01:12 AM   #15
Cirruslydakota
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Same here, the center vent closest to the drivers side always blows more than the one on the passenger side. But since im always the driver who cares? lol But really, its a design flay, a very strange one at that. Id suspect a seal leak of some sort and the only way to correct that is to rip the dash apart. Not a fun job for sure. FWIW, I got my two front windows tinted to match the rear and so far this has helped a ton!
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