Poor Idle/Stalling with Air Conditioner

ZippyZafira

Hey Guys

I have a 2002 Zafira which has just had a big overhall and is running great except when you turn the AC on..
When the AC is turned on it keeps stalling when idling at stand still

If you turn the AC off it runs like a dream and does not miss a beat.

If you are at idle with the AC off it idles perfect but if you turn it on it stalls instantly

Car has a new Alternator so i don't think its a power issue 🙁 any ideas?

evocarlos

has the ac been refilled at some point ? it could be to much gas in the system causing extra load

corsaZ22se

sounds like its not increasing engine idle rpm when aircon is on. pressure switch faulty or not reconnected? or blocked valve in air con system. located where pipe go into/out off evaporator on bulk head?
does the aircon work if you hold revs up?

ZippyZafira

Yep air con works fine... it has not had the air con refilled

car generally is running great. just cant figure out why it stalls when the air con is on

ZippyZafira

Interesting development.. we have just noticed it only stalls when the car has heated up and the thermo fan kicks in on the radiator (not the air condidtioning fan) BUT it only stalls and drops revs while the AC is on.. if its off then the thermo fan has no effect on the revs

corsaZ22se

with air con on I think both fans should come on when up to full temp?
they did on my Vectra b any way? do both fans work at both speeds? could be a fan motor fault drawing to much current and the extra load stalls the car?

ZippyZafira

They seem to spin fine. I disconnected the aircon fan and the same still happens. When the thermo fan first kicks in it nearly stalls. If the AC is switched off it does not drop in revs at all when the thermo kicks in.