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-   -   AC problem..Suggestions? (http://www.wranglerforum.com/f210/ac-problem-suggestions-20376.html)

sonofabeach 08-02-2008 03:38 AM

AC problem..Suggestions?
 
Hey y'all.
In the last couple of weeks on my 04 Wrangler I've noticed that sometimes the air blows and sometimes it does not. At first I thought the compressor/fan went out but then it started working again. Now it just comes and goes when it feels like it. When it's working, all of the vents work from floor to defrost and face so I don't think it's the "bent door" problem that I recently read about on here.
Does this sound like a switch or sensor problem? Should I take it to the shop or is it something you can possibly fix yourself?
It sucks because I don't use my air that much since the top is off half of the year.
I tried some electric contact spray on the knobs and at first it seemed to work but it went back to screwing up a couple of days later. I'll spray it again today and see if it helps again.
Seems like as soon as I fix one thing on my Jeep something else goes out :banghead:

47MTP 08-02-2008 03:48 AM

Check the connection to your blower motor; left rear as you face the engine. It's a two wire plug with a rubber boot around it to keep water out. Look and see if there's evidence of arcing, meaning it's not always making good contact. My plug wriggles loose and I have to re-seat it about once a week.
Bert

kcruisin 08-02-2008 08:41 AM

It's probably low on gas, put a can in it. A survice kit is around $20

slf41002 08-02-2008 11:09 AM

Does the air just turn warm,does the blower kick out like you turned the switch off,or does the air just start blowing out of another vent location???If it is turning warm you could have one of a few problems,low freon,bad compressor clutch,bad limit switch or a leak,if it is the blower kicking out or slowing it could be the resistor pack,control panel relays,or the blower,if it is coming from a different vent than the setting is on it is a vacuum problem.

4.0l sahara 08-02-2008 11:24 AM

If the blower is running but it isn't blowing where you have it set that could be then a vacume probleme.;)

jdhallissey 08-26-2008 12:53 AM

I have this same problem- when I am stopped at a light I can feel air coming through my vents but the minute I start moving the air only comes out through the defrosters. Any ideas there?

rrich 08-26-2008 01:10 AM

JD and Son --- It could be a vacuum check valve problem.
Try to notice if the blower actually stops working or it just gets diverted. That's going to tell whether it's electrical or vacuum.

When you are sitting still, decelerating, or just plain cruisin along with no load, vacuum is high, the heater/air doors operate normally.

But accelerate even a little, go up a hill etc, vacuum drops. If the vacuum to the heater/air doors drops, those doors change positions - not always all the way, but to an unwanted position - stopping proper airflow.

There's supposed to be a check valve in the vacuum line that may be leaking. The check valve holds the vacuum to the doors when vacuum was high so it doesn't keep changing when it drops.

Not sure exactly WHERE that check valve is - maybe someone with a manual can look it up. Probably a less than a $5 fix.

jdhallissey 08-26-2008 05:58 AM

Quote:

Originally Posted by rrich (Post 258400)
JD and Son --- It could be a vacuum check valve problem.
Try to notice if the blower actually stops working or it just gets diverted. That's going to tell whether it's electrical or vacuum.

When you are sitting still, decelerating, or just plain cruisin along with no load, vacuum is high, the heater/air doors operate normally.

But accelerate even a little, go up a hill etc, vacuum drops. If the vacuum to the heater/air doors drops, those doors change positions - not always all the way, but to an unwanted position - stopping proper airflow.

There's supposed to be a check valve in the vacuum line that may be leaking. The check valve holds the vacuum to the doors when vacuum was high so it doesn't keep changing when it drops.

Not sure exactly WHERE that check valve is - maybe someone with a manual can look it up. Probably a less than a $5 fix.


Thanks yea my air diverts. It always goes to the defroster.

richp 08-26-2008 07:36 AM

Pull the panel under the steering wheel, that gives you direct eyeballs and access to the vac motors. On my 97 the lever on the blend door was broken and the defroster blow path would not work if I gave it any fan, fixed it with a screw. The vac motors you can actually watch them work as you change positions on the vents, I'd look there first.

jeffsjk 08-26-2008 08:05 AM

sounds like the blower motor reastat.
If i am reading the post correctly, your saying the fan works intermittently.

rrich 08-26-2008 12:13 PM

03's and newer, maybe even a little older too, the BLEND door is a computer controlled double motor affair. One motor pulls the blend door to warm, the other to cool.

Symptoms are the air isn't diverted to the defroster like in this complaint, it just stays warm or cold no matter how you set it. My 03 Rubi had a bad ground somewhere in the wiring harness that made it warm all the time. Of course it was summer. Dealer wanted to replace the entire dash harness. I didn't want that - too many other places to go wrong. We just ran a new ground.

But, this sounds more like the air is being diverted to the defrost vents - that's controlled by the vacuum motors. They control doors that divert the air (either warm or cool) to the floor, dash, or defrost vents. As someone said, you can see them working when the dash panel is removed.

But - the complaint says intermittent, more than likely it changes due to manifold vacuum variations when driving. Parked it's probably fine.

It's totally dependent on the manifold vacuum, kinda like the old vacuum operated windshield wipers - on acceleration or times of low vacuum, the wipers stopped!

Since nobody has responded as to WHERE the check valve is, look for the vacuum line that runs through the firewall. Get a small vacuum check valve at a parts house (a discount place like Autochina won't have any idea what you are talking about - you'll get that dumb stare) - there are lots of variations of them - DO NOT GET A VACUUM DELAY VALVE - they look similar.

I'm not sure, but I think the HELP line has them. $2?

Cut the vacuum line where it goes THROUGH the firewall and put the check valve in series with the line.

If you put it in backwards the air will be diverted wrong all the time, you'll know it's in wrong.

In the right way the complaint should go away, it should go back to working right.

Let us know.

sonofabeach 12-05-2008 06:42 PM

After checking all connections under the hood I finally took it to my mom's boyfriend (who is a mechanic) the other day and in less than 2 minutes he found the problem.
I did not get a good look at it yet but he said the problem was a wire connection heading into the blower underneath the dash on the passenger's side.
He said the connection must have been loose, causing it to arc and weld together making it hard to seperate and giving it a bad connection.
He seperated the connection, scraped it with a knife, hit it with some contact spray and now it's good as new.
So easy I wish I would have taken it to him months ago.

Thanks for all of the ideas guys
Whew! Just in time for the brutal Florida winter.


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