Aircon - climate control

RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

Hi,

I have searched but found nothing unless I did not type the correct lingo

Synopsis - '05 CRD KJ - the aircon works like a dream at idle untill approx 1500rpm, after that it cuts out and the air gets progressivly warmer :shock:

At 2000 rpm I can hear the compressor switching on and off via the "clunk" sound as well as listening to the engine revs.

Work done - The main pipe with the orifice has been replaces, aircon fan replaced, system gassed and oiled.

Something else I have noticed is that when I go up a long hill in hot air the engine temp climbs to approx 2/3 on the guage then I nurse the KJ for the rest of the hill. Once I am over and go easy on the gas she cools off and runs at normal temp ( a touch below half on the guage )

When I have the aircon off on a warm day the aircon fan will run to keep the water cool - I have seen the radiator fan running at that time but it looks to me as though the raidiator fan is lazy. Would the aircon fan help cool the radiator water if the main fan is not running correctly????

If I have a lazy viscous fan, would that be causing my aircon to go completely mad

Any help would be great as I have spent far too much cash on this !#$%^@%&@$& problem :banghead:

WolverineFW · **Posted:** Mon Jan 02, 2012 7:58 pm

Was it doing this before or after you had the work done?

If it was after, did the system get recharged with the correct amount of refrigerant and type of refrigerant? Was the system evacuated properly with a vacuum pump? Did you change your dryer?

Sounds like your high pressure switch is short cycling your compressor due to excessive head pressure. (This is only an educated guess since I have not seen actual guage pressures on your system)

This could be due to an overcharge and/or non-condensibles in your system.

RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

It strted this nonsense before I had any of the work done. The correct type and amount of gas is in the system. It was done by a company that does only aircons and they have very nice electronic scales to measure the gas input.

The last time I gassed it we added dye so the next step is to check for a leak I guess unless as you say it's the pressure switch.

My mate had a 3.7V6 and I wonder if that uses the same pressure switch - I could use that to test :idea:

tjkj2002 · **Posted:** Tue Jan 03, 2012 1:44 am

Sounds like a cooling issue.The ECM will cut the AC off under a load for power and during overheating conditions.Fix the cooling issue then see how the AC works.

Quote:

Something else I have noticed is that when I go up a long hill in hot air the engine temp climbs to approx 2/3 on the guage then I nurse the KJ for the rest of the hill. Once I am over and go easy on the gas she cools off and runs at normal temp ( a touch below half on the guage )

RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

I've just placed an order from rockauto.com for a fan clutch (viscous) so it'll take a week or so to get here then I'll install it and see what she does

RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

Right, so the new fan clutch is in and there is no difference :banghead:

I have even bridged the low pressure switch and that is making no difference at all. I think it has something to do with the values in the ECu telling the compressor to switch off :?:

I guess I'll need to take it to the independent agent I use so he can hook his kit up so we can look at the values in the ECu and tweak them if necessary

The temps here have been 120F this week so no fun driving a KJ with out Aircon :furious:

JL Rockies · **Posted:** Mon Jan 23, 2012 9:25 pm

Some CRD's run hot with no viable solution. My solution after chasing it since 2007 was to buy a 4Runner.

RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

It's still not working :banghead:

The next step is to disconnect all the aircon hoses and back blow them. I have a sneaking suspicion that there might be a blockage :roll:

jerry0503214 · **Joined:** Fri Feb 03, 2012 3:06 am **Posts:** 2

If it was after, did the system get recharged with the correct amount of refrigerant and type of refrigerant? Was the system evacuated properly with a vacuum pump? Did you change your dryer?

Sounds like your high pressure switch is short cycling your compressor due to excessive head pressure. (This is only an educated guess since I have not seen actual guage pressures on your system)

This could be due to an overcharge and/or non-condensibles in your system.

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RichardM · **Joined:** Fri Nov 05, 2010 4:58 am **Posts:** 21

There was too much gas in the system so we let some out and checked the gauges - seems to be the correct amount in there at the moment.

I have not changed out the dryer ever. Pls explain non condensibles?

WolverineFW · **Posted:** Fri Feb 03, 2012 9:37 pm

RichardM wrote:

Pls explain non condensibles?

Only two things belong in a refrigeration/ air con system..... Refrigerant and the corresponding refrigerant oil. Anything else in the system such as air or moisture among other things will cause problems with the system.

Aircon - climate control

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