Aircon Issues (climate Control)

[rayban76]

Hello all,

just looking for some advice on my aircon issue (ive got climate control) as i've not yet had the time to take it anywhere to get it checked out.

Ever since doing the Cam on my car I have noticed that the aircon is not kicking in (the clutch is not kicking in).

I have put power directly to the aircon clutch and it does work so cant be a clutch problem so was wondering if it was low on gas would that stop the clutch kicking in, is there some sort of low gas switch in the system ?

I have pluged in my OBD reader and am not getting any error codes for the aircon which is a shame because I was hoping that it would give me something lol..

When I did the cam I did have the aircon unit tied up against the passengers inner wheel well and I know that the black upper rubber hose was kinked so i'm guessing that may have caused something..

Does anyone have any ideas ?

Ray

[mif73]

Im pretty sure there is a low pressure switch in line somewhere.
Its to protect the compressor so it wont run dry.
When you find it, unplug it from the loom and measure its resistance, pretty sure it should be closed (low resistance) with pressure.
Then plug it back in.
If its open you could quickly jump it to see if the compressor clicks on.
Obviously dont run the comp for more than a few seconds if it is low pressure.

I thought it would have logged a fault for low pressure though?

[rayban76]

Thanks for the advice mif73,

Someone did say they thought it had one but I couldnt find it, I might have to consult the wiring manual and see if I can find it that way.

Yeah when I ran the compressor it was just briefly to make sure it wasnt the clutch that had gone on it.

Ray

[mif73]

Originally Posted by rayban76

Thanks for the advice mif73,

Someone did say they thought it had one but I couldnt find it, I might have to consult the wiring manual and see if I can find it that way.

Yeah when I ran the compressor it was just briefly to make sure it wasnt the clutch that had gone on it.

Ray

I will see if i can find my switch too.

[rayban76]

Originally Posted by mif73

I will see if i can find my switch too.

Cheers mif

[FAT245]

off the back off the compressior, there is a steel cylinder which is part of the Aircon Lines, this has two Electrical Connectors. Possible that one has been dislodged.

[rayban76]

Originally Posted by FAT245

off the back off the compressior, there is a steel cylinder which is part of the Aircon Lines, this has two Electrical Connectors. Possible that one has been dislodged.

Nope already checked those, all connected .. lol

[FAT245]

out of ideas then LOL...

[rayban76]

yeah same thats why i thought it might be a low pressure switch when low on gas

[FAT245]

i believe it is on that canister.

There is a big and a small connector.
I had a pressure error when i missed the small one.

Did you remove the engine loom completely from the car when the upgrade was done? or only from the top half of the engine

[mif73]

Originally Posted by FAT245

i believe it is on that canister.

There is a big and a small connector.
I had a pressure error when i missed the small one.

Did you remove the engine loom completely from the car when the upgrade was done? or only from the top half of the engine

On my s1 v8 that canister with the 2 sensors looks like an expansion chamber of sorts.
One of them must be a low pressure switch.

I was going to ask how you changed the cam without disturbing the gas lines but then i figured you must have pulled the engine out?

[rayban76]

I removed the plugs from the aircon but have installed them back again and not getting any error codes come up at all..

I just read that one of the 'clutch not engaging' problems is low gas so that could well be the problem, although It did work before so dont know if having the black hose kinked has caused the gas to leak ... looks like i'll have to get a pressure test done either way

[rayban76]

Originally Posted by mif73

On my s1 v8 that canister with the 2 sensors looks like an expansion chamber of sorts.
One of them must be a low pressure switch.

I was going to ask how you changed the cam without disturbing the gas lines but then i figured you must have pulled the engine out?

Nope didnt pull the engine out, managed to tie the compressor back against the wheel well and managed to move the condensor core enough to get the cam past it

[mif73]

Originally Posted by rayban76

Nope didnt pull the engine out, managed to tie the compressor back against the wheel well and managed to move the condensor core enough to get the cam past it

Good effort that.

Could be part of the leak problem too.

[rayban76]

could well be, hopefully not, it wasnt a big bend

[rayban76]

Well just did a few tests and while the car was running pulled the plug off the A/C Pressure Transducer and straight away the compressor kicked in, I let it run for a bit and the aircon was not getting cold so i'm pretty sure that its low gas now...
I pluged it back on the switch and the compressor still kept going but the moment I switched the AC off, then on again it soesnt kick in again until I remove the plug.

[FAT245]

wonder if there was or is a crack?

[rayban76]

Never used to be, AC always worked great but there could well be now ... will do a little more playing around tomorrow in the light and see if I can find anything but hopefully no leaks

[rayban76]

Also found this

[FAT245]

maybe it got damaged?
If you cant find one down your way, i have a 6CYL Set here...

[rayban76]

Souldnt have, I've still got the 6cly one from the car I wrecked so if need be I can use that (if it fits it lol), I'm going to try removing the Discharge Temp Sender plug and see if it could be on the opposite way (doubt it but worth a try lol)

[FAT245]

or it was just a co-incidence lol.
6cyl one should work fine.

[rayban76]

Originally Posted by FAT245

or it was just a co-incidence lol.
6cyl one should work fine.

Just looked at the 6cyl one and they look the same, also looks like the small plug could possibly go on the wrong way, not sure if that would make a difference but will try that tomorrow anyway.

[FAT245]

i doubt it, as i think it is just a pressure switch if anything.
Wouldn't hurt to try, only wondering if you remove the sensor if you will get a nice green spray in the face or not..

[rayban76]

yeah cant remove it without the system being de-pressurised so I wont even try that one ... if swapping the plug around doesnt change anything I'll just take it doen and get the pressure test done

[mif73]

Hi Ray.
On the pic you attached it seems the pressure switch is actually a transducer which means it can read variable pressures, too low, too high and just right.
And you also have a variable temp sensor.
If either of those is disconnected or faulty you would get no engagement of the clutch.

Try disconnecting a plug on each while running and see if you get a code?

[rayban76]

Thats good thinking, will do that tomorrow morning and see.

As mentioned before the moment i disconnected the Pressure transducer the compressor started up straight away, I plugged it back in and the compressor still ran but i wasnt getting cold air through the vents.

I will try tomorrow and see if I get a code when doing that

[Davehoos]

the small sencor is a gas temp sencor,if no gas in system the temp will be room temp-and at 450 it will be hot. the bigger is a pressure transducer.
transducer does control the compressor but it purpose is more to control the radiator fan-if the pressure doesn't change at a rate that programmed then the compressor will turn off thinking that clutch is slipping or the belt has fallen off.

the transducer shares a 5 volt circuit wire that joins near the air box and ive had to solder these at the joiner.I had these fail and not set a code or not fitted when the car was made.

It works out if there is gas in the system or the belts/clutch are slipping. from the 2 imputs. if one imput fails the compressor can still operate.

rule of thumb is if compressor runs-radiator fan is at low speed. hold small steel pipe near air cleaner.warm before orifice-cool after. if its freezing its restricted .if they are similar then it has a gas issue.

radiator high speed--over gassed or condencor problem--transducor failed.

accumulator cold at the bottom and no cold air inside--heater or vent door issue.

good luck.

after the no gas or fryed compressor most common fault is thermostat and heater tap.then heater blend door.

[rayban76]

Thanks for the advice that's great detail, I felt the small pipe last night and it felt like the same temp before and after orifice so kinda thinking it's the no gas .... But will still have a play around and see ...

Thanks again, great advice

Ray

[Ride]

Ray, can't remember where I read it but there's a special diagnostic mode for the climate control units - that's where the faults get logged (as opposed to the ECU, air-con only relates to BEM as opposed to an engine thing that the ECU controls).