Air conditioning compressor not engaging

Obviously, now that it is 30+ degrees, my air con has failed, despite frequent use recently.

The compressor will engage if I give it a direct 12v feed. I have checked the two fuses. The switch lights up but I haven't been able to test the switch yet. It was regassed about 6 weeks ago and was blowing very cold up until an hour ago, which would seem to suggest it isn't low on gas.

Any suggestions before I take a day off work to get it sorted?

Cheers.

Get the pressure checked first, if it was re-gassed a few weeks ago there is a possibility that the fill valve may not have sealed properly and had a very slow leak to the point where the pressure switch stops it operating. Alternatively they could have disturbed something else while working on it or a stone may have punctured the condenser. If you then know the pressure is ok and the pump works when hotwired then the actual fault 'should' be fairly simple to find, the only potential issue could be if it is a pressure switch fault but you should be able to check that fairly easy. However I don't know if it needs to be open or closed when the pressure is correct.

Great , thanks for the info.

The truck gets used hard for work so damage to something is possible. I'm not sure if it's a coincidence but today I noticed that the water was only dripping out the passenger side. Further investigation showed drivers side was flooded. I've taken the 1way bung out and about half a litre of water followed. Two hours running time later, it stops working.

Anyway, as long as there isn't some hidden fuse somewhere that no one knows about. Ill get it booked in. Needless to say, no one can get me in till next week I guess I'm not the only one....

I had this problem. Been re-gassed, all electrics looked OK, check on dash unit gave no faults, all pipe work looked OK and clutch would engage with a direct feed. Took the lead off the dual pressure switch and things seemed OK (voltage at connector, no resistance at switch) but by-passed the pressure switch and clutch engaged. Made sure the contacts were clean and the connector was seated tightly on the switch and it's been fine since.

Feathers McGraw said:

I had this problem. Been re-gassed, all electrics looked OK, check on dash unit gave no faults, all pipe work looked OK and clutch would engage with a direct feed. Took the lead off the dual pressure switch and things seemed OK (voltage at connector, no resistance at switch) but by-passed the pressure switch and clutch engaged. Made sure the contacts were clean and the connector was seated tightly on the switch and it's been fine since.

Click to expand...

Ok great. I'll have a look at the pressure switch now. With it working perfectly and then just nothing, I'm finding it hard to believe it's the gas, unless of course it was a sudden release.

The ac was being a bit funny when the car was idling (having my lunch) it would switch on and off every few mins, even though the interior was piping hot.

That's made me think, I wonder if the ac would turn off from a faulty climiate control sensor...

I'll check the pressure switch first. Get that ruled out (hopefully in).

Feathers McGraw said:

I had this problem. Been re-gassed, all electrics looked OK, check on dash unit gave no faults, all pipe work looked OK and clutch would engage with a direct feed. Took the lead off the dual pressure switch and things seemed OK (voltage at connector, no resistance at switch) but by-passed the pressure switch and clutch engaged. Made sure the contacts were clean and the connector was seated tightly on the switch and it's been fine since.

Click to expand...

So glad you found this thread. It was the switch, or rather the wires running up to it. Jiggle jiggle jiggle, clunk, on it came. Ill have to have a proper look when I get home this weekend... But for now, it's working. Thanks mate.

Larry365 said:

So glad you found this thread. It was the switch, or rather the wires running up to it. Jiggle jiggle jiggle, clunk, on it came. Ill have to have a proper look when I get home this weekend... But for now, it's working. Thanks mate.

Click to expand...

I was gearing myself up to a new compressor etc. Nice when it's so easy to sort though! Glad to help.