Quantcast
Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

bradleyheathhays

Problem w/ intermittent defrost a/c

Recommended Posts

Have a '11 Crown Vic with 290k miles and I've been having a problem with the windows fogging up all the way around. The defrost seems to be working about half the time. On humid rainy days it'll work for say a half hour keeping the windows clear, then the windows will fog hard for 10-15 mins. And then it might decide to start working again, back and forth it goes. When I started it just now the compressor clutch turns when the a/c is turned on, although I haven't had a chance to observe it when the windows are fogging.


A secondary problem it has is that it only blows air through the vents on the front of the dash, straight out into the cabin. The air flows only very weak out the defrost vent at the windshield or the floor. It does this on all settings. Although this might contribute somewhat to the problem, it seems like the a/c does completely cut out as the windows will still fog hard with the a/c set to on and on full fan. When it cuts off the air in the cabin feels immediately humid. One that that helps somewhat is to turn the temp toward cooler and it seems to not fog as much and gives it a chance to maybe clear the fog some.


Any idea what's causing this or what I should do to start testing?

Share this post


Link to post
Share on other sites


This is quad crazy not crown Victoria crazy! Lol just kidding. It could be two things.  One the fogging could be due to a blown (heater core). It’s a small radiator type coil under dash board on the passenger side. A real bitch to get to.   A tell tale sign is the fogging as well as a wet floor on the passenger side under or on the carpet and a bit of a sweet odor in the car. 

The second thing it could be (less expensive) is the change over valve.  It’s a small valve or damper that’s controlled by the switch in the dash.  The control switch you would use to change to defrost to dash vent.   That switch usually activates a motor of a kind that moves the flaps inside the dashboard ductwork.  That motor can be a pneumatic , electric or cable depending on the year.  It’s usually located on the firewall under the hood. In that general area.  I’m putting my bet on the heater core though based on the fogging.  

Hope this helps.  Get an Atv. It’s a lot easier and more fun to work on! 

Sorry to my fellow members but I couldn’t help myself I love cars as well! 

Good  luck!  

  • Like 2
  • Haha 1

Share this post


Link to post
Share on other sites

hahahahahaha  lol thats hilarious that he just started posting about his car like a boss on an atv forum

Share this post


Link to post
Share on other sites


Yeah the B stands for Boss yall.  Haaaar.

Sorry it's been so long since I posted.  Life got complicated all the sudden.

I'd guess the heater core too if the dang thing just hadn't gone bad a few months back and I changed it out in 20 deg weather, yeah.  The fogging problem was going on before the core leak, it just happened to go as well.

Now that it's gotten a little warmer I've ran the a/c a little and it's doing the same thing it did last summer.  The air temp alternates between somewhat cool and not much cool, never getting down to cold.  I would guess I'm looking at 2 problems here but if I could just get the a/c problem fixed I wouldn't mind just having the air come out the vents.

Any ideas on how to start testing my a/c?

 

Share this post


Link to post
Share on other sites

I think Autozone has the gauges that you can hook up to the a.c unit and see if there is enough coolant and tell how your compressor is working.

They do a lot of tests for free (hoping you will buy there :) )

Mike

 

Share this post


Link to post
Share on other sites

I'm gonna assume my problem is being caused by low refrigerant and take a shot at fixing it as cheaply as I can. But at the same time I'd like to take steps at identifying where the leak might be.

So what will this look like? Renting some gauges from the local car store and checking my refrigerant lines? How would you go about this and what readings should I be looking for?

And then if things read low I would get a can of refrigerant with leak revealing dye and put it in the system?

Sorry I'm so remedial here, first time working on an a/c system.

Share this post


Link to post
Share on other sites

Its two gauges with some hookups to check the high and low pressure side of the compressor. If you do have a leak you can buy refrigerant that contains a UV dye in it so you can identify the source of the leak using a UV light.

Autozone will do some tests for free, or you can rent the gauges to do the test, or take it to any garage. No use spending money for the gauges for a one time use.

Mike

 

Share this post


Link to post
Share on other sites


Assuming that's R134 which it should be, you can use one of those quick blast R134 cans with an indicator gauge and just top it off. However, are you show your climate controls are working correctly, blend door, etc.? This is from Amazon, but you can find it at the auto parts stores, walmart, etc. Has sealer and oil  in it also.

R134 AC recharge

Share this post


Link to post
Share on other sites

Hooked the gauges up and it seems like I've got a low refrigerant condition. Before turning the engine on both gauges read about 75. After starting the engine and setting the AC on max you could really tell the compressor was cycling fast. The needles cycled every 5-6 seconds...one going up and the other down, then reversed. The blue gauge cycled between 22 and 38 PSI while the red went between 90-140. The outside temp was about 60 F.

From what I've read, especially with the compressor cycling so fast, this indicates low refrigerant. Hopefully my compressor isn't hurt by running it for so long like this.

How do I go about using this 2 gauge setup to add refrigerant? Should I add it through the middle hose somehow or get a can of 134 with a gauge on it and just add it directly from the can?

And how do you know how much to put in?
 

Share this post


Link to post
Share on other sites

The fast cycling of the compressor is because of the low pressure, This is to prevent damage to the compressor.

Offhand I don't know what the numbers should be as far as pressure for normal amount of refrigerant, im sure you can look that up.

Mike

 

Share this post


Link to post
Share on other sites

After I took the gauges off I noticed one of the schrader valves was hissing, and now the system is down to 0 psi.  So I believe a faulty valve has been the culprit all along.

Now that the system is down I'm going to replace both valves, but my regular schrader valve removal tool won't fit down on the valve.  The stem of the valve is too long and the tool won't go down around it to twist it out.  I need a tool with prongs longer to fit down into the recessed sides of the valve.  Does this '11 Crown Vic have schrader valves or a different kind of valve?

Also, when I go to fill the system with refrigerant, do I need to add any PEG oil or just add refrigerant up to the specified capacity?

 

Share this post


Link to post
Share on other sites


Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By Julio Cano
      The tires which I bought on ebay cannot be balanced, it’s out of round.Tried riding and had wobble. 
      It was mounted in shop and they also put it on a rim they had sitting in the shop and same issue to confirm it.
      Are they defective ?
      They have brand new high quality tires for my  old suzuki gsxr750 and want about $600 for two tires.
      Is it worth it to pay that much or buy another set of front rear tires like Hexautoparts which has good reviews on trustpilot.com?
      Any recommendations ?
      Thank you.
    • By dgk_mike
      It will go into neutral, 1st, 2nd, and reverse but nothing after 2nd gear. The shifter moves freely going up completely nothing but when you shift down it works. I’m not sure if it’s tranny issue worth messing with or if I should just buy a new one.  Overall besides that the thing runs like new.

    • By dany desbiens
      Hello i have a Polaris 2003 sportsman 600 Polaris Sportsman OEM Gauge Speedo Speedometer Display Dash Cluster 3280425 the speedo is not working no 4*4 i can find nothing can i put a speedo 2004Speedometer Gauge Speedo
      3280431 04-08 Sportsman if it will work
    • By Venom
      Hi All,
      I did a total restoration on a 2003 Yamaha Raptor 80. Rebuilt the engine and tranny.. Started it up today and it runs great. Took it for a ride and the transmission worked perfectly. Adjusted the carb a little more and went for another ride. It ran awesome, pulled into the workshop shifted into neutral ( Neutral light came on) and shut off the bike. went to roll it and noticed she would not roll. Turned on the key and neutral light was on... After some troubleshooting I found that she is in first gear with the neutral light on and will not shift into neutral... It seems to up shift fine into 2nd and 3rd and then back down to 1st. I am hoping somebody can shed some light on what is happening... Thanks for any help...

    • By jrhoads23
      I picked up a 2017 Polaris Sportsman 850. The previous owner rarely rode it and it only had 53 miles on it (10 hours). I believe the Polaris break in period is something like 250 miles / 50 hours or something like that at which point they suggest doing the first oil and fluid change. My question is should I do it sooner than that? I believe this was manufactured in fall of 2016 so that means the fluids in there are 3 years old. Maybe that isnt a big deal and it is still fine to wait until 50 hours, but just wanted to check
  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...