air con problems

[bwanathefirst]

hi there,
I recently replaced my ac compressor as the original one was noisy, aircon was fine...didn't use it as I had the roof down..
I then replaced the climate control unit as half the display pixels were missing when I try to use the aircon nothing.... its supposed to come on automatically
if the outside temp is above 0c ,,you then de select it using the econ button[ that switches it off] I've tried putting the old climate control back still nothing
the gas is there... any suggestions???
pete

[9-3 Aero]

Was the compressor working, with soft top raised, before the replacement?

One feature of the convertible ACC system's (programmed) operation is that when the soft top is lowered is the A/C turned off -

Fuses in question: # 5 in the engine bay fuse box, and # 19 in the instrument panel fuse box (however supply for ABS and rear fog lights as well).

[bwanathefirst]

hi
yes air con was working with the top raised had the top down and went to Lancashire came back via Nottingham,, had a stage one remap done by saabnoob,
he did a good job as he had to fit a few extras [ I have an eco turbo] now she flies... def feel the boost. anyway I digress.
he had a spare acc unit which I took off him everything works [all leds buttons etc] except the air con... roof closed nothing she blows warmish even put my old acc back no difference
will recheck fuses using my multimeter

[9-3 Aero]

Beware of that it is the engine management system which grounds the A/C relay when all conditions for an A/C request are fulfilled. Could something have happened as an unforeseen effect of the remapping?

[bwanathefirst]

hi
checked the fuses all ok spoke to karl at saabnoob he says the the remap wouldn't affect the operation of the air con, he checked the old map against the new and there wasn't any conflict
so I'm thinking maybe the compressor???as that's the only other change I've made.. my unit was noisy that's why I changed it..is it worth having it reconditioned as it was working previously

[9-3 Aero]

Hi.

The engine management system (ECU) sends the A/C request to the compressor clutch by closing relay "J" in the engine bay relay central (box), to engage the compressor. This given all four conditions for the request are fulfilled. So this relay could be in question. What you could do, to see whether the relay closes or not, is pulling the plug at the compressor, connect the positive pin of a multimeter to the plug and negative to chassis. Given the A/C request is sent from the ECU, should the meter show +12V - or voltage as charged.

If not, you could pull the relay, connect positive multimeter on pin # 5 (85) of the socket and negative on chassis. A reading towards +12V indicates that the A/C request is not sent from the ECU. Or you could simply replace the relay and note change - if any.

EDIT: BTW, what model year is the 9-3?

[bwanathefirst]

hi its the 93 se 2 litre turbo soft-top [year 2000] its been well looked after and has a full history.. the previous lady owner had the ac compressor bypassed ,she always had the heater on
I'm intending on taking the car with me when I return to south Africa and aircon is a must there.
on your comment the a pos 12volt reading on pin 5 indicates that an a/c request is not being sent from the ecu.. so then I should have 0volts on pin 5??

[9-3 Aero]

Correct, when all the conditions for the A(C request are fulfilled, the ECU grounds (0volts) the relay at pin #5, thus the relay contact closes and provides 12V for the compressor clutch - from fuse # 5.

Seems to be a nice car

[bwanathefirst]

[bwanathefirst]

missed the text button.. need to get a better pic