Air Con: clutch not engaging

[elkopi]

Hey all,

I noticed my air con not working in my 2002 v40 1.9TD. I recharged it and it still did not work. Then I noticed that the clutch does not engage. I checked the fuse and it is fine. I went to the cycle switch and bypassed it.

Now, I do not know if I did it correctly. There are three prongs on the switch. I would expect there to be two (+ and -). What are the three prongs for?

I tried to connect each pair of prongs separately and all three together, just in case and did not here any 'click' sound indicating that the clutch engages. I did not see the clutch, because I was doing it on my own. I was just trying to hear it going on and I could not.

I would very much appreciate if someone could explain to me what's the three prongs on the air con cycle switch and how should I bypass the switch?

Thanks in advance,

Mac.

[960kg]

If your talking Pressure Switch jump the two outside terminals, you can use soft wire solder, but you still have to put the connector back on!!!.......to hold the jumped wires in place and also to allow the dashboard switches to operate the A/C

Although this switch allows the compressor not to engage when the pressure is low to save the compressor from damage or getting too hot.....there is also a fail safe Temp. Sensor in the compressor itself which will turn it off to prevent damage.

Best not to go that far, just in case, but i used to turn the a/c on and off manually after 15mins of running until i wanted to re-gas but never did i sold as was.

It does sound as though the switch has failed.

[elkopi]

hey 960kg,

thanks for reply.

I did use soft wire solder but I do not know which prongs on the switch to connect. There are three of them.

Also, if after bypassing the switch, the clutch still does not engage does that necessarily mean that the switch is bad, or may it be something else?

[960kg]

On my 960 it was the outside prongs but try all in a different sequence it can do no harm ,it will work or not!!....some models vary on the wiring circuits.

Have patience as sometimes when pushing in the connector it will move the jump wire!!.....just keep doing it until you are happy or not happy....

Your easier pushing the solder wire up the connector holes

If the switch is yay ok, then a shim has to be removed from the compressor clutch end to give it closer clearance.....a bit of a job!

[elkopi]

ok, so i did push the wire inside the connector, not the switch (two left ones when you look so that the metal safety thing is on the top) and the clutch engaged but only for a second, i could hear the freon being circulated in the system but after a second or so it went off again then after a few seconds it went on again but again just for a second or so.

i did not have to put the connector in the switch which i guess makes sense. why would the clutch disengage again? is there any other safety switch or is it something else?

also does it mean that the clutch is fine?

[960kg]

Probably still low on gas pressure to run ok.

[elkopi]

thanks for your patience 960kg,

if it was low on gas pressure, than bypassing the switch would make the clutch running anyway, wouldn't it? if it disengages it means that there's either some other safety switch, or something else which I do not understand.

Is that correct?

[Dog_Book]

Originally Posted by elkopi

thanks for your patience 960kg,

if it was low on gas pressure, than bypassing the switch would make the clutch running anyway, wouldn't it? if it disengages it means that there's either some other safety switch, or something else which I do not understand.

Is that correct?

yes, i had a similar issue which is def no gas as mine leaked again shutting of the pump. Search for my posts and you'll see i have a massive hole in a AC pipe worn through by the power steering pump

[960kg]

Originally Posted by 960kg

If your talking Pressure Switch jump the two outside terminals, you can use soft wire solder, but you still have to put the connector back on!!! This allows chips on the PCB board on the dash to operate the system properly.......to hold the jumped wires in place and also to allow the dashboard switches to operate the A/C

Although this switch allows the compressor not to engage when the pressure is low to save the compressor from damage or getting too hot....there is also a fail safe Temp. Sensor in the compressor itself which will turn it off to prevent damage. This may also be a lower pressure switch?

Best not to go that far, just in case, but i used to turn the a/c on and off manually after 15mins of running until i wanted to re-gas but never did i sold as was.

It does sound as though the switch has failed.

Originally Posted by elkopi

ok, so i did push the wire inside the connector, not the switch (two left ones when you look so that the metal safety thing is on the top) and the clutch engaged but only for a second, i could hear the freon being circulated in the system but after a second or so it went off again then after a few seconds it went on again but again just for a second or so.

i did not have to put the connector in the switch which i guess makes sense. why would the clutch disengage again? is there any other safety switch or is it something else?

also does it mean that the clutch is fine?

The clutch sounds fine as it worked albeit for a second.

Originally Posted by elkopi

thanks for your patience 960kg,

if it was low on gas pressure, than bypassing the switch would make the clutch running anyway, wouldn't it? if it disengages it means that there's either some other safety switch, or something else which I do not understand.

Is that correct?

You don`t know how much pressure of refrigerant you have in there!......so things won`t work properly until it has the correct pressure even if it is lower than the Pressure Switch limit.

Look at the pics. to give you an idea how it`s done.

You really are better off going to an AirCon specialist who will tell you where the leak is ,if it has one seeing as you say you put some gas in.

When the compressor runs the gas pressure has to be within limits as well as the temp. of the compressor.

Although owners say Volvo have built in obsolescence they do also have built in safety features to SAVE you money!

[elkopi]

i went to the aircon specialists and they emptied the system, checked it for leaks (none found) and put new 850g of freon, then they refunded me half a cash .

I noticed something strange. As I mentioned before there are three prongs on a connector. When i connect the two outer ones i get the increase in the engine idle and when i connect the two left ones i can hear the gas flowing in the system quite rapidly. Also not dependant on any bypassing (or so it seems) i could hear once or twice the clutch engaging for a sec.

As you can guess I'm totally lost.

Volvo garage charges £100 just to look at it, so I would prefer, if possible, do it on my own.

Anyone has a clue what is it please?