Air Con blowing warm but pressure correct

[DelBenz]

I have one of these Halfords DIY regassing kits which was used last summer to good effect. The aircon is now blowing warm. I checked the pressure myself and it showed normal. I popped it in to Halfords and they say the pressure is exactly what it should be and that I might have a flap or vent jammed. '98 W208,

 

[DelBenz]

Dont think its the Duo alves

After perusing the threads I did a bit more diagnostic work ( Good stuff on these threads !). Having learned what a duo valve is, I popped of the connector and checked continuity across both valves - OK about 25 Ohms ( I think ). across the connector I have 12 Volts on the common pin in the middle and OV on the outer - seems OK. This does not change with any of the temperature adjustments in the car. Putting the connector back on I can feel the slight 'Thump !' as the coils energise. I have no idea what the motor/pump device further down the circuit is doing. I would assume from my tests that the Duo Valves are thus OK ( ???? )

There are no leaks in the system as the pressure is normal. Adjusting the temperature controls does affect the temperature slightly but on a warm day - the coolest it will get to appears to be outside temp.

Any ideas ?

 

[42864]

I don't know if this will be of any help but ---- My car a S Class (140 series) had problems with the heating A/C system and after checking the Duo Valve and electrics, it was found that there are 3 Temperature sensors in the car, -- 1 in the roof alongside the curtosy light and 2 more in the Centre Consul ( behind the Radio and the Heater controls) these sensors are only a coupleof pounds each ( about 4 or 5 pounds) from memory, once these were changed the Heater and A/C system worked perfectly, now I do not know if your model is fitted with these sensors, but may be worth checking and finding out if they would / could have any bearing on your problems. I hope that this may be of some help, sorry if I have wasted your time.

Dave

 

[rf065]

Have a look at this, http://www.youtube.com/watch?v=PqNR7PGuE1s

especially the part about a one way valve that makes it look as though the pressure is OK when the system may be almost empty.

Russ

 

[nickcc101]

Tried the recharge kits and the pressure gauge, still u/s. Sent car to aircon specialist and worked o/k since (18 months).