Ac cools a bit then warm? May have found the fix.....

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Bigkevschopshop

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Its summer, the heat is in full swing in August here in Texas... So, I had my truck checked and recharged about 3 weeks ago.. it worked great... did a 500 mile weekend in the ole 12 burb... So earlier this week, my ac started not to want to blow cold and the clutch was cycling like it was preventing freeze up or something. So at least it wasn't the dreaded blend door crap. I searched and searched, some say pressure switch, some say aspirator... But I didn't think it was the pressure switch but still not 100% sold on it.

So I have heard the aspirator inside the truck can get clogged, dirty, etc... IT's basically a MAF style sensor inside the truck with a fan to bring air over it. I remembered that mine made some high pitch buzzing sometimes, very light and hardly noticeable but my range of hearing is pretty high and low.. Was thinking yesterday that I haven't been hearing what I normally do, maybe its because the fans been higher... So I saw my computer duster sitting on my desk... Decided, hey why not see if my ride home actually gets better than 60-70 degrees out of the vents...

SO you know that little round microphone hole above your head in the drivers seat... aspirator.jpg

YEAH the one everyone tries to talk into when someone can't hear them... That's the aspirator for the climate control... So few good hits with the air duster, then fire it up and hit it a few more times, now its quiet as hell but will hold a small piece of paper up to it so the fan is working.

Hit it with the tube on, do not angle can just use the tube to direct in through the grill, about 1/4" to 1/2" away at first, then you can go up to 1/8" this allows the fan to get some spin and not be shocked by a huge flow, at least that was my thinking.

duster.jpg

AC starting cooling normal on the ride home... But was blowing that VAPOR COLD GOLD...My vent temps on recycle and on blower 3 was 45-47 and outside temp was 102 on the display.. Blower all the way up only pushed us into the low to mid 50s... I was able to turn the blower down to 3-4 the whole ride home like i used to do... This is a 35 mile trip every day in the great ole Houston, so its an hour drive... Did a test and with it being 102 out, on outside air I was pushing about 58 degrees out the vents on high...Id say its working.

So hopefully this little hit of compressed air fixes the issue, I may need to do an aspirator soon but I figured I may as well share a bit of interior maintenance, or helping you get ac blowing better on a bad day... So its only a day into the fix but this morning I had about 45 vent temps on the way to work, never went off like it had all week...

So far just a couple shots of compressed air duster saved my big ass from being sweaty and pissed...
 
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wjburken

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I’ve cleaned that sensor on a couple of my vehicles only to end up replacing them. Easy swap if you have a sun roof and not too pricey.

My symptoms were a buzz in my ear because the little fan would start to clog up.
 
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Bigkevschopshop

Bigkevschopshop

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I’ve cleaned that sensor on a couple of my vehicles only to end up replacing them. Easy swap if you have a sun roof and not too pricey.

My symptoms were a buzz in my ear because the little fan would start to clog up.
Yeah I know that this isn't a permanent fix, just a get by for the time being... But its a good way to diagnose a problem without a scan tool. May get someone by till they can repair it is where I'm going with things.. Seems to be a normal wear out item after some years...
 
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Bigkevschopshop

Bigkevschopshop

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So update for anyone interested... Reset the control unit by pulling fuse 39 and relearn procedure... Its still had some struggling points after replacing that sensor.. SO I am almost leaning to the control unit having some issues... When it works I get 39 degrees out of it at night, 48 during day on recycle.. 100 degree plus right now here during day, night 80 degrees.. When it works its great... I have found that it only does it on certain drive cycles... It starts off ok then gets warmer, If I manually turn off the control and turn back on, it works about where it should be... Its just my luck that the one time a year my AC decided to give me shit was the time when we push into 100 + temps...

So anyone else who has experienced this issue before have any help to offer I am all ears... THe blow out of the aspirator worked as a get by for that one day on the way home, next it worked pretty good, I deiced to replace that sensor and a pressure switch while i was at it. The compressed air trick does work if your aspirator is dirty or stuck it seems mine may have had a little dust on it but I think we are getting to the full cause of my issues...

So spend the 250 for the control unit head on the dash or is it another faulty sensor?
 

Doubeleive

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If you do buy the head unit I believe it needs to programmed with a tech 2 @Doubeleive
depends-maybe, I bought mine from rockauto (new) when I installed it, it showed the outside ambient temp in the center of the display, seemed to work fine for the summer but when the weather changed and I needed heat in the back it would only blow hot if set to 89 or 90 anything less and it would blow cold, after a lot of troubleshooting I found out it was not the right firmware for my truck and it was looking for a rear sensor that my truck does not have, I had the dealer flash it to my vin and it's been all good since then, when they flashed it that outside ambient temp in the center went away, the temp of course was always still displayed in the cluster like normal, some of the trucks have it displayed in the rear view mirror. so my point is if you buy a replacement control unit after you install it make it sure it blows hot/warm/cold air in both front and back like it should otherwise it may need to be flashed to your vin.
 
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