Air Conditioner icing up???

[Benj73 Lurker Find all posts View Profile Close Benj73]

Hi, have a 2003 petrol GXL. Recently did a long trip from Sydney to Adelaide with 2-3 hour stints. Found that after a while the air conditioner became less effective and required more fan power to push air through. It also started to leak dops of cold water into the foot well. It appears that it was icing up. Turning it off for a period allowing it to defrost and it performed as normal for a while and then iced up again. Have not had this problem on shorter trips around town. Drain appears to function ok.

Any ideas? A sensor? Thermostat?

Thanks
Ben

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

Mate, i would say number one chk the filter, if that is blocked up it would cause a problem.

if that is not the case i would guess it would be the refrigerant charge in the unit, prob mean taking it some where unless you know a fridgie, but it prob means your looking at a leak.

[damonat Advanced Member Find all posts View Profile Close damonat]

i have been aware of this happening.
the vehicle was also a early 120 series.
i haven't heard of it happening to later models.
(only 1 vehicle out of probably 10-20 at my previous workplace)
we tryed heaps to fix it. new core, resealing system, hoses.
in the end toyota came up and spent 1 full day with the 2 technicans
trying to resolve it.
this was years ago (04-05), and i can't remember the fix.
i'll try and contact them and ask.
in the mean time someone else may have an answer

[Damien Parker Advanced Member Find all posts View Profile Close Damien Parker]

Sounds like an issue with the thermistor that senses the coil temp, holding the clutch in on the compressor.

It should cycle on and off to prevent exactly this problem.

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

Sounds like an issue with the thermistor that senses the coil temp, holding the clutch in on the compressor.

It should cycle on and off to prevent exactly this problem.

it could be, but i would think there is a higher chance of mechanical faliure, ie, gas leak than, an electrical fault...

[MickL Addicted PP Member Find all posts View Profile Close MickL]

I had the same symptoms with the split system in my office over summer, it was spitting ice out and struggling to cool.

The cause was low gas. I also remember the tech who fixed it saying that if it is left that the ice growing on the heat exchanger can sometimes break/crack the alloy tubes.

I guess it would be a good idea to get it checked by a fridgie... just for peace of mind...save a possible bigger bill later on.

Mick

[Guest Close Guest]

Moved to correct section.

[Benj73 Lurker Find all posts View Profile Close Benj73]

Thanks for the replies. Will have it in soon for servicing and see what I can find. Filter is ok. Will try a re-gas. The way it behaved seemed suggestive of a faulty thermostat (thermistor?), something causing it to get just that bit too cold. Will post the result.
Fearful of having a dealership spending a day looking for a problem (and finding nothing) which may only replicate itself again on the next long trip.
Speaking of which, can any of the Adelaide members recommend any particular workshops for servicing (dealership or otherwise)? Like similar posts on here I am concerned about paying good dollars to have it glossed over by an apprentice.

Thanks for the fast replies guys. Very impressed with the forum. Apologies for the double post. Clicked the wrong general section initially.

[Rainman Advanced Member Find all posts View Profile Close Rainman]

Probably nothing to do with your situation, but I had a similar problem in an old Camira I used to own (I did the Gibb River Road in it :shock,

The airconditioner used to frost up and leak freezing cold water down my passengers feet. It turned out to be a blocked drain. There was a self sealing rubber hose on the fire wall that used to get clogged up with dust and wouldnt let the water drain out, eventually it backed up and drained out into the passenger footwell.

I know my 90 series has a similar drain (but its a proper metal pipe), perhaps have a look to see if the drains blocked with some mud etc. Worth a shot.

[Up The Creek Junior Member Find all posts View Profile Close Up The Creek]

I remember reading a thread here sometime ago about this common problem in pre 07 Prado's.

Basically the sensor behind the dash is too close to piping or vents and freezes up.

There was a thread showing pics of how to get to it (sensor) and it needs slight bending and then wrapping in insulation before slotting back in.

If I can find the thread I will post.

[Up The Creek Junior Member Find all posts View Profile Close Up The Creek]

Here we go... i found it so informative that i saved the thread a year ago, in case my Prado had the problem.

http://paulpickford.com/prado/

[damonat Advanced Member Find all posts View Profile Close damonat]

good find. pretty easy to follow instructions.

[Benj73 Lurker Find all posts View Profile Close Benj73]

Great info. Thanks.
Will post with the outcome. Will need a long drive to test it again as it appears to be fine on shorter trips around town. Heading up to the territory in July so that should put the ac through its paces.
Cheers
Ben

[mcfisherclan Member Find all posts View Profile Close mcfisherclan]

Re: Air Conditioner icing up???

Hey mate,
Any news, i just had a long drive back from townsville and it was doing the same thing you described for the first time. Id really like to knock it on its head straight away. I dont really want to go pulling things apart if they dont help. cheers

[Benj73 Lurker Find all posts View Profile Close Benj73]

Re: Air Conditioner icing up???

Hi, I have now sold that particular Prado (2003 Manual GXL). I only had the problem a couple of times again and always on long drives. I was able to tolerate turning the AC off for short periods when it happened leaving just the fan running which was blowing through an iced up AC anyway and still slightly cool. Once things had de-iced, I then switched the AC back on and it was fine for a while. 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. The link posted above sounds promising though. Good Luck.