Testing AC Switches

[Tesla]

Hello,

The AC in my Car, Mondeo Ghia Mk2 is stuck on the hot setting.

It has done this once before and I managed to sort it by moving the heat selector from hot to cold a few times but now it seems stuck on hot. I don't mean warm air, I mean hot. Nice when it's cold but after a few mins it's like an oven!

I need to pinpoint the problem and have a suspiscion it's the heat selector control.
It's a rotary style control and on the back has one connector with 3 pins.

Is there any way for me to test the functionailty of this control with my multimeter? Is it basically a variable resistor?

Any advice much appreciated as the car isn't too comfy at the moment.

 

[DannyW]

Hi I had a fiesta with the exact same problem as this, i cant remember exactly but i think it was some heater control valve way behind the dash

 

[Tesla]

Hi I had a fiesta with the exact same problem as this, i cant remember exactly but i think it was some heater control valve way behind the dash

OK, I am not sure the best place to start so thought to start at the switch. Some faulty valve makes more sense.

Fortunately most Mondeo parts are dirt cheap so I am hoping for a cheap fix.

 

[DannyW]

good luck anyway ill never forget mine been oven hot too!!

 

[Tesla]

Any further ideas?

I don't know where the heater control valve is on the Mondeo. Someone said up behind the dash but I cannot see it.

My valve is completely electronic switch driven, older mondeos had a mechanical cable on the switch. Mine doesn't.

 

[willd58]

Its a common fault on the Fiesta, cant remember what the fix is. Might be the same problem you have got, but I doubt it.

 

[Tesla]

Its a common fault on the Fiesta, cant remember what the fix is. Might be the same problem you have got, but I doubt it.

What's a decent Fiesta forum where I can read up on it.

I imagine it's the same stuff as I bet they are the same part!