Hot, Cold, Half Hot Half Cold - Heater Driving Me Mad

[AlmorWalton]

Hi,

New to forum so hello! Really enjoying owning my 2008 Puma. I've had some interesting cars but never had one that gets so many admiring glances and compliments from strangers. Love the way all Defender drivers wave at each other too. Used to get that in my MG but no one does that when you're driving a Toyota!

The only thing is the heater/AC has a mind of its own. Generally, it blows luke warm to red hot wherever you put the dial. Every now and again, it will blow cold if you play around with the dial but it is totally random (eg: the dial doesn't necessarily have to be on cold for it to blow cold). Turning the dial back from hot to cold seems to have no effect. Depressing the AC button doesn't seem to change the scenario either. It is impossible just to have normal non cooled or heated air blow into the cabin too - only red hot (slight over embellishment there!). And just to really wind me up yesterday it was blowing lovely cold air from the round driver's side vent and red hot air from the passengers! Has anyone got an idea as to why it is doing this and how to solve the problem? I'm reasonably mechanically minded so would like to have a go fixing it myself if I can.

Thanks in advance and keep waving!

Almor

[AlmorWalton]

Hi,

First post so "hello". Just bought a 2007 Puma. Love it to bits - apart from the heater/AC which has a mind of it's own. The heater is generally blowing very hot when turned on. Turning the dial to cold doesn't have an effect. It still blows hot. Putting the AC on doesn't change anything either. Moving the air intake from exterior to interior circulate doesn't make any difference either. Every now and again, if i keep turning the dial back and forth, it will gradually start blowing cold (so the AC isn't the issue). And just to top of the performance, yesterday it started blowing red hot out of the passenger side round heating vent and AC cold air out of the driver's side. Anyone got any idea what is going on?

Thanks in advance

Almor

[DiscoMick]

Hi.
I have this problem. There are several threads about it
Open the bonnet and on the passenger side at the top you will see a white plastic fitting with several hoses going into it. It looks like this:
At the back is a cable connected to a black plastic slide. If you are lucky the slide is just stiff and needs oiling, so oil while moving it backwards and forwards. This may cause the tap inside the fitting to close completely and block warm water from entering. Should keep the air cold.
If not it means the fitting is warped inside and needs replacing.
They are a standard Peugeot Citroen Fiat part and made in China. If you search 'Defender Puma heater valve' you will find them on eBay for about $90. Britpart also sells them for about $135 posted from the UK. I paid US$28 from a Chinese site. Yet to fit mine.
JQD500080V.
Denso OE A. 232.001.0
PA66-GF30.

Hope that helps.
https://uploads.tapatalk-cdn.com/20181016/9fe240c898adb1c205fca55526235107.jpg

[DiscoMick]

Also, you might have the air con serviced. When I had mine done the workshop said the filter was blocked and looked like it had never been changed from the original.

[DiscoMick]

Right hand aircon vent not as cold. (https://www.aulro.com/afvb/90-110-130-defender-county/260063-right-hand-aircon-vent-not-cold.html)

[Tote]

In addition to the above most newer vehicles have a "blend door" that changes the temperature of the air by varying the ratio of air that is passing over the heater core (in addition to a tap that controls the flow of water through the core). A Defender only has the tap, so when you adjust the temperature from hot to cold and vice versa the core needs to change temperature in order to feel a change in the air temperature, this can take a minute or so, rather than being instantaneous with a blend door equipped heater.

Regards,
Tote