AC does not come on

Blista · Post by **Blista** » Fri Jul 26, 2013 9:25 am

There is a pressure switch on the gas circuit (I don't know where they put it on 5th gens).
If the gas pressure is too low (or if the switch is out of service, or damaged wiring harness...) the AC control unit won't allow you to turn on AC.

judderod · Post by **judderod** » Fri Jul 26, 2013 9:35 am

Does sound more like electrical then if it suddenly stopped. Leaks are usually very slow. Unless you crash the car. Then it's a bit quicker. As I discovered a couple of years ago when the mrs had a go at parking underneath the car in front.

Post by **Merlin** » Fri Jul 26, 2013 9:38 am

Yeah I think it is electrical too as I cannot explain the possible sudden loss of pressure. There are a load of trouble shooting flow diagrams in the service manual, check continuity of this etc... I guess I will have to go through them

I think the 2nd or 3rd thing it says to check is if there is gas in the system.

bb1boy · Post by **bb1boy** » Fri Jul 26, 2013 10:02 am

Can you do a DIY re-gas, from a can or something? Or do we have to pay £50 or whatever it is in Kwik-Fit?

craig_jdm · Post by **craig_jdm** » Fri Jul 26, 2013 10:24 am

Get a multimeter and take the switch out check the swith is working switch could be broken then if it is working work back to see how far the electricity makes it with a test lamp to check for breaks if all else fails.........rip it out

Blista · Post by **Blista** » Fri Jul 26, 2013 11:35 am

You can also bypass the switch for a few seconds and see if it works.

h10ndr · Post by **h10ndr** » Fri Jul 26, 2013 12:51 pm

Just updated my earlier post and added the utube vids for the fix procedure.

Post by **Merlin** » Fri Jul 26, 2013 6:53 pm

My air con came back on today, almost 24 hours to the minute since it stopped working. It was back to blasting ice cold air. Maybe I have some slugde that covered the pressure sensor

. Anyway seems as good a reason as any to get the system cleaned out and re-gassed.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Sat Jul 27, 2013 9:59 am

bb1boy wrote:Can you do a DIY re-gas, from a can or something? Or do we have to pay £50 or whatever it is in Kwik-Fit?

Kwik-fit won't do r12 built cars (which is what 3rd/4ths are, don't know about 5ths).

Can you still get DIY re-use kits? I thought they'd been banned?

I wouldn't bother with them anyway tbh, because you've got no idea if you've put the right amount of gas in, or the correct lube, or if there's a leak in the system etc. Use a mobile automotive A/C specialist.

Blista · Post by **Blista** » Sat Jul 27, 2013 1:07 pm

Some 4th gens are R134a, at least in France.