Air con not working on a 2010 fg 84 canter

I agree with Ivan. If it is low on gas it won't have enough pressure to keep the LOW pressure switch turned ON and so it looks to be ok but the main system won't work.

If you are talking about the fan on the condenser it may only work when required. Those systems are usually installed by the dealerships as a kit. The electrical are usually behind the passenger kick panel or under the grill depending on the model.
What do you do to get one or the other to work?

That is not a smart idea to bypass a fuse with a relay contacts action. No fuse = burn of something if wiring shorted.

DOES IT COOL AT ALL WHEN RUNNING???? That determines if GAS is OK or NOT.

There is a inline fuse going to the relay
It does get cold don't let it run for long as condenser gets hot
When I connect OT up to the relay it keeps going g even when I switch of the air con fan and turn of the air con
.makes me think it's not the right relay or my wiring is wrong

I assume the fuse was for the condenser fan?

Yes it worked after. The sparky put the relay in that was about 3yrs ago

Thanks mate I have had a mechanic look at it out of his league he said gas is full
He thinks it is a short or broken wire behind the dash
The auto sparky in town is uncontactable
The light on the switch comes on but nothing not sure how hard it would be to pull apart and check out
It has been on rough gravel roads all its life working fully loaded
Good to have someone with common sense reply
Gary

Gary
If the mechanic says the gas is full but the task "is out of his league" how does he know the gas situation? DID he run the compressor to see to see if there was a cooling heating exchange happen?

The aircon switch only turns ON a relay to power the system. and another relay and/or thermostat is closed to make the compressor magnet pull in the compressor clutch. If clutch isn't operating and there is sufficient gas, to turn on the low pressure switch, ie, always ON normally, then you are looking for a loos or broken wire or a relay which is sus. The relay which turns on system should click when aircon switched ON.

If the cutch is relay switched from the thermostat, that real opens and closes thousands of times and so may be stuffed. Substituting as others mentioned, would pin that down.

Does the evap/cooling bit inside, ie, the blower fan run? If not it is a main supply issue.

Hi
Yes he put guages on pressure is good
When he pit power direct air con works fine nice and cool
There is no clicking when I turn on the air con
Have put all new relays in
Blower fan works fine
Will have to track down a sparky I think
Gary

Does condenser fan unde lh front wheel work when ac turned on and cab blower working

Yes the in cab fan works not the out side one
If u put power to air con the fan at bottom doesn't work with air con working or power fan air con doesn't work
Tried power to air con and a separate power to fan fan cuts out air con
Have to be wiring fault I think
Gary

The fault is most likely condesor fan relay in box behind lh wheel inside lid is printed relay positions could be relay pin connections in receptacle loose or dirty. if you substitute known good relay eg horn relay you can test have good look atrela pins for signs of bad connection also check condenser fan fuse also in box or back probe with test light while still plugged in on top of each side of fuse ac will not function if condesor fan is not working as the condenser gets no engine fan due to mounting position everything else, will work but not cooling

No variable compressor on these have had same fault before as he stated condenser fan not running they just don’t cool usually the relay or relay connections condenser is little bugger mounted in front of lh wheel

The relay which turns ON and Off to control compressor MUST be checked first. It would fail before any other relay, because it cycles so often, ie, ALL THE TIME.

Well finally found another auto sparky
It was the thermistor burnt out quick easy fix
Thanks for all the help
Gary

How was it a THERMISTOR. They are simply a TEMP SENSING DEVICE and carry miniscule current. ie cannot burn out. However, it may have become faulty and stopped the system switching ON.

It does have a burn mark on it will put a photo on it up if I can
Works well now $100 fix
Hary