Have had the air con regassed recently. When I use the aircon on the windscreen it is nice and cold, however when i press auto it just belts out hot air through the vents. Any ideas, sensor problem perhaps?

When you press that windscreen button I dont think it uses aircon???

 

Life the bonnet and press your 'auto' button and see if the clutch on the compressor actually goes on.

The front of ot should spin.

To check sensors, go into self diagnostics on the climate conteol panel by:

 

1. With the ignition switch turned ON, Press AUTO and OFF simultaneously for 5 seconds (step 2 in 1.). This will activate the Monitor Diagnosis Mode (step 3 in 1.)

 

2. Pressing AUTO again will switch to the Actuator Test Mode (step 4 in 1.).

 

3. Pressing AUTO again will switch to the Upper and Lower Temperature Difference Adjustment Mode (step 5 in 1.).

 

4. Pressing AUTO again will switch to a readout of Trouble Codes (step 6 in 1.).

 

5. Pressing AUTO again loops back to Monitor Diagnosis Mode (step 3 in 1.).

 

 

 

Cant remember if its no,4 or no,5 will display 50/50

 

then you can scrol through these with either the fan 'high and low' on the side, or 'rec/econ' button. cant remember now, lol.

 

If theres any error yuou will get a line on the bottom horizontal or vertical, open or short circuit. If theres no error its a number.

 

LOOK HERE

 

Theres more info HERE (goto 'tech' on the left side, then auto aclimate control is near the bottom.) but its for a '95 model and found it didnt help for my '90 model.

Cheers rodders

 

Have gone into diagnostic tests, the sensors all read normal temps apart from the VENT sensor, which is -62. I assume this could be the problem. Anyone know where to find this sensor, and how much to replace it would be?

 

Thanks a lot.

The windscreen defrost does use the aircon.

 

I had the same problem as you when the sensors were disconnected under the dash.

I'd had the air pipes off that feed the door vents and without the sensors connected that are in that pipe the system just blows hot air out.

 

Take the panel off under the steering wheel and you'll see the air pipe.

You might have to remove the pipe to get to the sensors but I'm not sure.

 

Suppose this could apply to one of the other sensors in the system though so could be a lot of searching and I'm not sure how you test if it's a faulty one.

The windscreen defrost does use the aircon.

 

I had the same problem as you when the sensors were disconnected under the dash.

I'd had the air pipes off that feed the door vents and without the sensors connected that are in that pipe the system just blows hot air out.

 

Take the panel off under the steering wheel and you'll see the air pipe.

You might have to remove the pipe to get to the sensors but I'm not sure.

 

Suppose this could apply to one of the other sensors in the system though so could be a lot of searching and I'm not sure how you test if it's a faulty one.

 

How would you know you used yours for extra balast in the boot. :rofl:

 

You have to ensure that the sensors are connected even if the pipes are missing for any reason and you just tuck them out of the way. If they are disconnected and cannot read the temp they will run the the system at hot all the time.

 

There are 2 sensors one in the top hose and one in the bottom. If its Ok on screen then its the bottom one thats missing or unplugged. check both anyway.

 

If however this does not resolve it then it could be the control arms on the climate control deflector plate. ie it's not closing the heating bit shut. These often get disconneted during heater matrix replacement and sometime reinstalled incorrectly. If this is the case you will have to remove all the radio and centre pannel to check. I'm affraid if it is this its dash out time to reconnect. Before you go to that level check the climate control ECU is OK as above. May need disconnecting for and hour to reset.

 

Hope its just the sensors cos the dash out is a full day and a real bitch.

 

P.S. you could always do what Chris did and call J the Gun :slap: :nono: :rofl:

Sounds very complicated. Think I might just take the roof off instead!!! Thanks for your help guys I will look into it.

Before you go to that level check the climate control ECU is OK as above. May need disconnecting for and hour to reset.

 

what may need disconnecting for an hour to reset? just installed a new amb temp senser it still reads -86 i thought i may need to reset it but didnt know how?

 

thanks for the help

paul