Aircon Probs

[Grumpy stumpy]

Can anybody shed some light on a aircon issue I have please, had my trusted garage take a quick look for me f.o.c. And filled system up but they have checked everything and found there is no supply to the compressor, fuses ok etc but no life to it, just wondered if anyone else have had similar issues, they said could be a ecu problem but not 100% or more likely broken wire, was going to run a temp wire from Battery to compressor just to try and see .any ideas appreciated please.

[LeeADAB]

Probably not the solution but you do know that the aircon button only works when the fan speed is set to ON or higher? The amber light on the Aircon switch is not lit until the fan speed is set.

Might be of help?

Cheers,

Lee

[Grumpy stumpy]

Probably not the solution but you do know that the aircon button only works when the fan speed is set to ON or higher? The amber light on the Aircon switch is not lit until the fan speed is set.

Might be of help?

Cheers,

Lee

Yes mate thanks anyway. When fan selected a/c button flashes instead of being on steady. Fans all work just no supply to compressor, looks like there's two relays one from fan to condenser fan and one from fan to ac control assembly . Might have a look at these.

[Big Kev]

Wife's did this only a few weeks ago Phil.......aircon serviced and recharged at Mr.T....PREY HESTO.....all fine.

The light FLASHING is the hint that the coolant's a goner.

[Grumpy stumpy]

Wife's did this only a few weeks ago Phil.......aircon serviced and recharged at Mr.T....PREY HESTO.....all fine.

The light FLASHING is the hint that the coolant's a goner.

Hi mate, had it topped up this morning but still no joy. Garage done me a favour as didn't charge me and just fitted in between jobs, just removed the fan relays and refitted and ran and everything worked fine, left running for 15 mins no probs lovely and cold,stopped and then put back on and same fault where light flashes so a unusual one! You can here engine not change as if compressor power cut then stops working.

[Parts-King]

I would suspect it is detecting a fault and kicking the compressor OFF to save it being damaged, the same way it does it when the ambient air temperature is too cold. It could be something along those lines, a temp sensor switch failing or similar

Kingo

[Grumpy stumpy]

I would suspect it is detecting a fault and kicking the compressor OFF to save it being damaged, the same way it does it when the ambient air temperature is too cold. It could be something along those lines, a temp sensor switch failing or similar

Kingo

Cheers kingo, can't get it to work again now, as soon as you press the the ac button it works for a couple of seconds then cuts the compressor so could be a sensor failing etc. not sure how to test sensor though, looks like its two pressure switch's one on the compressor and one near the H port. Where would the temp sensor be located?

Cheers

Phil

[Parts-King]

There is an ambient temp sensor behind the grille, it is different for cars with and without A/C so that might be one to check, there is also a cabin air temperature switch under the dashboard drivers side too

Kingo

[Grumpy stumpy]

There is an ambient temp sensor behind the grille, it is different for cars with and without A/C so that might be one to check, there is also a cabin air temperature switch under the dashboard drivers side too

Kingo

Thanks kingo will have a look.

[Grumpy stumpy]

There is an ambient temp sensor behind the grille, it is different for cars with and without A/C so that might be one to check, there is also a cabin air temperature switch under the dashboard drivers side too

Kingo

Well been looking this eve and think I may have located ambient sensor just above number plate behind bumper, how on earth you get to it without removing bumper I don't know, and can't locate anything that looks like a sensor under drivers side dash, so looks like I am going to have to get an aircon specialist to sort out or live without it. Hate it when I can't fix it myself, can't be major as had it working on and off.

[IanXT4]

I wonder if there are any diagnostic codes stored ? I have a climate control version and I believe that these ecu codes are accessable, but only with the Toyota Techstream hardware/software diagnostic kit.

I had a similar problem with a Golf, the compressor would not engage.

VAG diagnostics showed that the low/high pressure switch was faulty.

A simple £20 fix that did not even need the sytem to be drained.

I have attached the document for the codes available on the climate version.AC diag codes.pdf

[Grumpy stumpy]

Thanks for that, the garage said there were no codes listed at time of checking which is why we have drawn a blank, they will have another look for me if I wish or they have a aircon specialist they call in if they can't fix it. They have been great and have not charged me for regassing and checking out . May have to bite the bullet and give the aircon guy a call.

[Tech01]

Another thing to check out is that the correct quantity of new refrigerant/oil has been added. There is a label on the underside of the bonnet saying, IIRC, that quantity is 100gm. This is for a "topping out" (via the sight glass) only. The total quantity from evacuated empty is 510gm +/- 10gm.

Don't get caught out by the vehicle's label. Your symptoms do suggest a lack of refrigerant.

Chris

[Big Kev]

Another thing to check out is that the correct quantity of new refrigerant/oil has been added. There is a label on the underside of the bonnet saying, IIRC, that quantity is 100gm. This is for a "topping out" (via the sight glass) only. The total quantity from evacuated empty is 510gm +/- 10gm.

Don't get caught out by the vehicle's label. Your symptoms do suggest a lack of refrigerant.

Chris

.........which is what T. told me the FLASHING light was solely for.....?

[Grumpy stumpy]

Another thing to check out is that the correct quantity of new refrigerant/oil has been added. There is a label on the underside of the bonnet saying, IIRC, that quantity is 100gm. This is for a "topping out" (via the sight glass) only. The total quantity from evacuated empty is 510gm +/- 10gm.

Don't get caught out by the vehicle's label. Your symptoms do suggest a lack of refrigerant.

Chris

Thanks chris hopefully that will all it will be, will get chap to have a look at will report back. Could be that as had it drained and refilled then drove home twenty odd miles and after dinner went out and tried it and it worked ok, left it running 15 mins and turned off. Restarted and tried, then had same fault, maybe coolant settled down and requires more.

[IanXT4]

Coolant does not settle down, the correct amount is either in, or leaks out

Your AC system is meant to have a specific quantity of coolant gas and a special (PAG) oil.

When the AC system is first started at the factory the correct fill of oil is in the compressor. As the system runs it distributes itself around the system such that after an AC system is stopped it estimated that the following oil % apply.

PAG oil %

Compressor 50%

Condensor 10%

LP hose 10%

Evap 20%

Drier 10%

When they refill the AC system the special service machine should remove the coolant gas/oil and weigh both. It then vacuums the system to check for leaks and adds the correct full quantity of coolant gas for your car plus the exact amount of oil removed. (most of the oil still stays in the system, even when vacuumed)

If a component is replaced when the system is drained down, (say the compressor) you only add the estimated oil that was expected in that component (50%). Too much oil is as bad for an AC system as too little. (I would suspect that you have the correct fill of oil in your system)

The AC service machine only checks for leaks with a vacuum, I had one leaking system that only leaked when it had a positive pressure inside.

The fact that it worked after a drain/fill makes me think you might have a slow gas leak. The service machine usually adds a UV dye to the coolant , have the garage shine a UV light to look for possible leaks. Low pressure would definitely cause the compressor to kick out.

When they serviced the system the machine usually produces a printed sheet showing the amount of oil and gas recovered. If there was very little gas removed it would indicate that the system was leaking prior to its service.

[anchorman]

I doubt any local garage would do what is necessary for free. As Ian has pointed out it has to be done properly or that light will flash for ever more.

[Grumpy stumpy]

Thanks guys for your replys will get the ac expert out and get it sorted.

Phil.

[Big Kev]

Coolant does not settle down, the correct amount is either in, or leaks out

Your AC system is meant to have a specific quantity of coolant gas and a special (PAG) oil.

When the AC system is first started at the factory the correct fill of oil is in the compressor. As the system runs it distributes itself around the system such that after an AC system is stopped it estimated that the following oil % apply.

PAG oil %

Compressor 50%

Condensor 10%

LP hose 10%

Evap 20%

Drier 10%

When they refill the AC system the special service machine should remove the coolant gas/oil and weigh both. It then vacuums the system to check for leaks and adds the correct full quantity of coolant gas for your car plus the exact amount of oil removed. (most of the oil still stays in the system, even when vacuumed)

If a component is replaced when the system is drained down, (say the compressor) you only add the estimated oil that was expected in that component (50%). Too much oil is as bad for an AC system as too little. (I would suspect that you have the correct fill of oil in your system)

The AC service machine only checks for leaks with a vacuum, I had one leaking system that only leaked when it had a positive pressure inside.

The fact that it worked after a drain/fill makes me think you might have a slow gas leak. The service machine usually adds a UV dye to the coolant , have the garage shine a UV light to look for possible leaks. Low pressure would definitely cause the compressor to kick out.

When they serviced the system the machine usually produces a printed sheet showing the amount of oil and gas recovered. If there was very little gas removed it would indicate that the system was leaking prior to its service.

...........ah knew that........lol......Mr.T was only 45gbp to do full service Phil, not including new pollen filter which you do yursell.

[dwilson]

I had a new pollen filter and air con service at my local main dealer for £85. It seemed fine before but it does smell fresher now.

David

[Grumpy stumpy]

Well kev will give Mr T a ring as just spoke to a so called aircon expert who doesn't want to know ! Told him what it was doing and said could turn out to be a knightmare job and wasn't interested .

Phil.

[Grumpy stumpy]

Just spoke to my local Mr T £79.99 for a standard service but when I told them it was flashing they said it only covered a service fault investigation would be additional to that without the cost of parts which I knew would be extra. Live with it soon be winter !

[IanXT4]

Quick question

When you recently had your A/C serviced and checked for codes, was it with a Toyota garage ?

If A/C error codes are stored on your model, i am pretty sure you cannot read them with a standard OBD2 reader that most independant garages have. You will need the specialised Toyota code reader that covers A/C.

Codes for A/C, ABS and other specialised components require special Toyota software to read and diagnose.

Engine parameters by Law have to be readable by an OBD2 reader (for MOT's emissions etc), other systems don't.

So the car manufactures make them non standard, I guess to ensure you have to use their services.

I still think your system should be throwing a code ?

[Grumpy stumpy]

Quick question

When you recently had your A/C serviced and checked for codes, was it with a Toyota garage ?

If A/C error codes are stored on your model, i am pretty sure you cannot read them with a standard OBD2 reader that most independant garages have. You will need the specialised Toyota code reader that covers A/C.

Codes for A/C, ABS and other specialised components require special Toyota software to read and diagnose.

Engine parameters by Law have to be readable by an OBD2 reader (for MOT's emissions etc), other systems don't.

So the car manufactures make them non standard, I guess to ensure you have to use their services.

I still think your system should be throwing a code ?[/quote

Independent toyota garage mate, not sure what code reader they have, may pay me to pay the extra and get Mr T to service then see how much they want extra to investigate.

[Grumpy stumpy]

Does any body have a wiring diagram and system layout for the a/c system please, 2004 petrol rav 4.2.