Ford Scorpio Forum - Print Page


    
      
        Ford Scorpio Forum
        (https://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl)
      

        General >> Problems >> HVAC problem
        
(Message started by: Whatever on Nov 6^th, 2013, 8:55pm)

Title: HVAC problem
Post by Whatever on Nov 6^th, 2013, 8:55pm

My 1998 2.3 Estate with the fully automatic climate control sometimes shuts of air delivery through the various vents no matter where i set the control knob. Fan is working and temp is OK but nothing comes out of the dash or other vents.

Title: Re: HVAC problem
Post by Snoopy on Nov 8^th, 2013, 7:41am

Have you done a reset on the system?

If no the procedure is HERE (http://www.fordscorpio.co.uk/ccreset.htm)

Some of the code you get may vary but the procedure is identical

Title: Re: HVAC problem
Post by Whatever on Nov 8^th, 2013, 11:29am

Done the reset, but no change or codes

Title: Re: HVAC problem
Post by Tompion on Nov 9^th, 2013, 5:26pm

Thinking this through, there are 3 flaps controlled by the climate control (4 if you include the recycled-air flap).
1 flap controls the air going to the windscreen or the floor vents, depending on the dial setting it can shut these off. Because it’s a single flap it affects driver & passenger sides the same.

The other 2 flaps control the temperature to the face vents, 1 for the driver’s temp setting the other for the passenger’s temp. These flaps do not have a closed position – fully one way bypasses the matrix = cold, fully the other way through the matrix only = hot, somewhere between = the desired temp. With the fan running the only way to stop air to the face vents is manually at the outlets on the dash.

So if your fan is definitely running there must be a blockage.
One possibility is a fault with the aircon whereby the compressor keeps running instead of cycling so the evaporator blocks by icing up – all incoming air passes through the evaporator. Even with the aircon light off it will still be running if you have the dial set to windscreen.

The evaporator is upstream of the pollen filters so next time it happens try removing the pollen filter cover if air starts to flow through the vents you’ll know the problem is before the filters, remove a filter & feel how cold the evaporator is.
I assume you’ve checked the pollen filters although I wouldn’t have thought they’d give an intermittent blockage.

It’s possible there’s a blockage with leaves or whatever before the evaporator or on the evaporator but that’s difficult to get at – you could try putting it onto recycled air since that opens a flap inside the car behind the dash immediately in front of the evaporator instead of air coming through the external intake.

Title: Re: HVAC problem
Post by Whatever on Nov 9^th, 2013, 9:37pm

I have checked the filters and they are dirty, but I have cleaned them so the filters are not blocking anything. I will try removing the filter cover and see what I can find. The blockage is not affected by different settings on the control panel

Title: Re: HVAC problem
Post by Whatever on Nov 15^th, 2013, 6:37am

Problem seems to be that the compressor doesn't cycle and icing up the evaporator. Faulty temperature sensor or high pressure switch?

Title: Re: HVAC problem
Post by Tompion on Nov 15^th, 2013, 10:55am

I take it no one's done the booster mod & it is set too low:
http://www.fordscorpio.co.uk/acmod.htm

They won’t necessarily have put a control where the headlight leveller is.
Have a look down the side of the blower box to see if there are any extra wires as shown on the mod page.