2003 Focus AirCon wont turn on

sunset06 · 10-02-2011, 01:40 AM

So, last year my 2003 focus AC compressor was leaking, and dealer said it needed replacement (1500 + install). I went for the reco'd one instead. Worked well (if maybe a bit noisier than original compressor - only 50,000 kms).

Lately, I've found that the AC button LED no longer illuminates, and neither the compressor nor the extra cooling fans turn on.

Up on ramps, I found that nothing occurs when I try to push the AC button (~ oh yeah, the fan is running (on any of the 4x speeds !). However, if I put the rotary dial on demister (ie air to dash), then the cooling fans startup, the revs drop slightly, and after a while cold air is blowing on the windscreen.

I've taken a quick look at the wiring schematics from AFF, but it looks like there is numerous modules that can be going wrong, or it might just be the physical switch (which appears to be a momentary push button).

What do you think ? Is it a common problem ? Anybody like to loan/sell the tool (Melb) to get the radio out (ST-170), so I can investigate further ?

Riksta · 10-02-2011, 01:59 AM

I think from memory they have a pressure switch, so if you have low to no gas then the compressor won't kick in. That's what I've heard in general, not sure if its your specific problem though.

sunset06 · 10-02-2011, 10:49 AM

Quote:

Originally Posted by Riksta

> compressor won't kick in.

I wonder if the protection logic would be different between pressing the A/C button compared to turning on with the windscreen demister setting (which does work and chills the window). ie: the designers might have thought it a safety issue to be able to see out the windscreen, and hence allow the compressor to start even though it is essentially in fault (pressure / gas) condition ?

I saw info to carefully check the temperature of the low and high pressure piped. When on demist, the compressor clutch does activate, and after a minute, the two pipes from the compressor: one get's real hot, while the other gets really cold.

20focus05 · 13-02-2011, 01:05 PM

Check fuses for the A/C, demister may use different circuit?
If the pressure switch was faulty it would not let the A/C system work even with demist.
You can demist a windscreen with out A/C just that it dries the air faster.

Thought of taking it to a A/C place?

sunset06 · 14-02-2011, 10:07 AM

Quote:

Originally Posted by 20focus05

Check fuses for the A/C, demister may use different circuit?

Yes, checked both under bonnet and behind glovebox, but I think I'll double check...

Quote:

Originally Posted by 20focus05

If the pressure switch was faulty it would not let the A/C system work even with demist.

Thought of taking it to a A/C place?

Yes. I don't know any in Melb central/north-west. Would you recommend an AC specialist over the ford dealer ?