Air Conditioner icing up???

[wes Senior Member Find all posts View Profile Close wes]

Re: Air Conditioner icing up???

It seemed to be affected by the amount of air being forced past the fins by the fan. If the fan was up high, it seemed to have less of a chance of icing up. But if the fan was on a constant low, the problem returned. Sorry I cannot be of more assistance here. I never bothered to investigate it further as it happened only occasionally but still annoying.""

this is true as part of the refrigeration process.
less airflow across the coil means better heat rejection/transfer resulting in cooler air.

what were the settings you guys were running at the time it iced up?ie fresh or recirc air and what was the ambient conditions at the time ie high humidity and temp or low temps and high humidity?
have seen a split system fully iced up on high humidity days yet runs fine any other day.
also agree with the possibility of the coil sensor not sensing/responding quickly enough.
have not had ours ice up yet and have done a few trips with it on all the way from wollongong to melbourne and same on the return.

[Benj73 Lurker Find all posts View Profile Close Benj73]

Re: Air Conditioner icing up???

Mine iced up on Recirc air which is what I generally have it set on. AC fan was set to level one or two just to keep the cabin temp comfortable running, almost running in the background but certainly noticed when it started to ice up and almost no air coming from the vents followed by ice chips and cool water once it started to thaw. Outside temp was about 29 degrees and it was in SA where we dont get it too humid. It certainly was a fault somewhere and tending to think the sensor.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Re: Air Conditioner icing up???

This was common on most 03/04 prados. It was icing up due to the air from the fan that should pass through the evaporator but was actually blowing around the box due to the foam packing that should have been around the evap (inside the box). This was fixed by toyota by pulling the evap out and replacing the foam packing. I was only talking to 2 mates yesterday about this problem who have worked for Toyota for nearly 20 years each. Mine is the other way around, its cutting out to quick before it gets cold enough out the vents, Should come out somewhere around the 5c give or take a degree or two, mine coming out at 8.8 then climbing back up to 11.2, am moving the thermistor on sunday away from the evap a bit to cool it down some more. Anywhere around the 5/6 will be fine. Regards Steve

[aussieranger Lurker Find all posts View Profile Close aussieranger]

Re: Air Conditioner icing up???

Hi all, we are still having this issue on long drives in our Prado (2003) and as stated it only seems to happen on long trips. The thermistor suggestion seems to ring true but I'll keep an open mind. I'll also have a look at that post earlier with the link to a suggested fix. Will let you know how I go.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Re: Air Conditioner icing up???

Doubt its the thermister, there is very little room in the evap box for it to be too far away from the evaporator to cause it to freeze up. I managed to move myn away from the evap a bit and have got the temp down to just on 6 degrees coming out vents which is fine. I had to take the thermistor out of the box (still wired up) and drop it down on the carpet before it would get down to 3 d or lower (which would cause it to freeze up) which you wont be able to achieve if thermister is still inside evap. I still reckon you have the problem of the air not going through the evap properly (previous post by myself), unless you have a faulty thermistor ?? maybe see if you can get one from a wreck and try it out or a new one if available, very easy to remove and replace, just pushes in evap one end and have a plug the other. Regards Steve

Hi all, we are still having this issue on long drives in our Prado (2003) and as stated it only seems to happen on long trips. The thermistor suggestion seems to ring true but I'll keep an open mind. I'll also have a look at that post earlier with the link to a suggested fix. Will let you know how I go.

[desmond Junior Member Find all posts View Profile Close desmond]

I managed to move myn away from the evap a bit and have got the temp down to just on 6 degrees coming out vents which is fine. I had to take the thermistor out of the box (still wired up) and drop it down on the carpet before it would get down to 3 d or lower (which would cause it to freeze up) which you wont be able to achieve if thermister is still inside evap. I still reckon you have the problem of the air not going through the evap properly (previous post by myself), unless you have a faulty thermistor ??

Hi all, I have the exact same problem in my 2003 LC4 here in the UK, long trips and air con shuts on/off every 20sec and not cooling the cabin fast enough during summer. Now, the car is still under toyo extended warranty for 2 more months and toyota service have been fighting with this problem for a very very long time but no luck.

So, having read this post now what would you recommend I shall do...print this forum thread for the toyota service folks and ask them to look at the thermistor and potentially replace it? or try to fix it on my own and move the termistor as per instructions above...

what do you think, any hits?

[Matty80 Avid PP Poster! Find all posts View Profile Close Matty80]

Best bet, might be worth trying it yourself - only cost you for parts and not labour... Have some fun in the process?

[charlie Junior Member Find all posts View Profile Close charlie]

I have always found the aircon too cold in cars. The Prados a/c is so powerful it ejects air at about 8 degrees C. I spoke to the service people and they said this was normal, so I checked up, Yep lots of cars are about this temp. You can put the heater on to warm the cold air up a little but it seems so inefficient to cill the air to heat it up again. Has anyone got a more comfortable temperature by shifting the thermister alone?

[hisham saeed Member Find all posts View Profile Close hisham saeed]

well here is my story with my 2006 petrol with dual Ac part of it was icing perhaps it could help:
first i had a jammed damper/gate (driver side cold air only ,while passenger side cold & hot air) repaired with only a touch of finger tip !!
when it was getting warmer i then switched to max cold and oooops (driver side HOT air only ) i took the car to unauthrized service center and the nightmare begain
guy said don't worry , but you'll have to leave the car for tonight as we must take the the dash board off the car to get to the dampers and we will put new one (later i discovered he fix it woth a metal pin at the end). apart of some elctrical problems which was due to unconnected plugs under the dashboard, the AC is not working probarly , it works fine for about 30 minutes and then no cold air, i went to another AC specialist and regased with 1000 gm, still the same, went to another and told my story they told me that the car is overgased and it should take 800 gm , i said go ahead , car regased still AC is not the same before the damper issue + icing up , took the car to TOYOTA , after waisting a day their , they called my name and tols me that i have to leave the car for 5 days as they discoverd the AC is icing up and they will have to check the Ac, left them full of anger.
went to a third AC guy , told my story and he told me that somthing went wrong while assembly the evaportaor & coil, this one told me to come early in the morning to finish the car same day , took the day off ,went next morning , dash board is out , evap looks ok he told me.
i asked then what is wrong he told me must be the gas, the car is back togeather but this time with a few plastic clips broken.
time to regas the car, all done same problem again .
at the end went to my mecahnic , when he knew he told me that i have a bloked cycle , we found a little filter at the front of the car attached to the AC radiator, you can reach it from under the car . he told me that all i'm going to loose is the price of the gas , and i agreed , changed the filter regased the with 800 gm all working fine, then i relaized that the AC cutting off time is too long and i remmbered that last time the coil was out the thermister wasn't in its original place , iwent to my mechanic again took the dashboard out again i did it my self this time and repalced the thermister back in place without removing the evaporator box , all is working fine now,
my guess is try the thermister yourself , then if problem still there check the gas level.

hisham

[hisham saeed Member Find all posts View Profile Close hisham saeed]

and here is all the AC realted thread i could find:

http://www.pradopoint.com/showthread...r-conditioning
http://www.pradopoint.com/showthread...heater-problem
http://www.pradopoint.com/showthread...-cool-not-cold
http://www.pradopoint.com/showthread...ion-thermistor

hisham

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Why the hell they removed the dash to play with the thermistor is beyond me, you can get to it in 5 minutes just by removing the glovebox lid and panel behind, took me 5 minutes, mine wasnt freezing up but wasnt coming out the vents cold enough 8 to 11 degrees, its now coming out about 5 to 6 which is great for the hotter weather. Seems to be a few issues with these climate control units shooting hot/cold /cold/hot etc out different vents, Well at least now yours is fixed again, your a very very patient man, my god I would have sold it before what you have been through LOL. Regards Steve

[hisham saeed Member Find all posts View Profile Close hisham saeed]

hi steve
what year is your prado ?
mine is 2006 the thermistor is not reachable as described above, now i regret i didn't take photos, you can only reach the thermistor plug from behind the glove box, but the thermistor is actually attached ti the coil by two small pins (one is metal which i think is responsibale for sensing the temp. & the other is plastic for keeping it in place ).

and yes i did consider selling the car.

hisham

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Mine is 05 GXL so is not climate air like your VX or the grandes untill in 07 when the climate duel air become standard. Here is an attachment/link showing what the thermistor looks like. I didnt bend mine at all, I just slid it down the plastic holder a bit. The thermister in mine is held in by the plastic clip, just give a gentle pull on the clip itself (Dont pull on the wire) and it slid out, fair dinkum 2 minute job. Here is the link http://paulpickford.com/prado/ Regards Steve

[mancman Lurker Find all posts View Profile Close mancman]

I have the same problem,about to change my thermistor when it arrives,anybody out there done this yet? I cant open the links supplied above for some reason.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

http://www.pradopoint.com/showthread...03-Cold-Aircon may help you out....Cheers Steve