Ok dumb question, the heated rear screen, how long is the operating cycle?.

5-10 mins I think before it turns itself off. I kow it's on longer than the front screen. 2006 Mercedes CLS
1991 Retro-style Mini
But really finding it hard to fight the urge for a S/C...

10 minutes, but it stays on low power for a further hour.

This should be fine to defrost the rear window - there should be no steaming up inside the car because of course you leave your Air Con ON All Of The Time

Rear Window Heater
When the engine is running and the rear window heater is selected on, the ATC ECU illuminates the LED above the switch and energises the rear window heater relay on the rear fusebox. After 10 minutes (when ambient temperature is –15 °C (5 °F) or above) or 17 minutes (when ambient temperature is less than –15 °C (5 °F)), the ATC ECU extinguishes the LED and operates the rear window heater at low power for 60 minutes. During the 60 minutes, the ATC ECU cycles the rear window heater relay off for 80 seconds and on for 40 seconds.

If the rear window heater switch is pressed again during the low power phase, the ATC ECU illuminates the LED again and returns the rear window heater to full power by keeping the rear window heater relay energised for 5 minutes. At the end of the 5 minutes the LED is extinguished and the 60 minutes low power phase is repeated.

The ATC ECU outputs a K bus message when the rear window heater is active. The message allows the navigation computer to compensate for the effect of the magnetic field generated when the rear window heater is active. The BCU transfers the message onto the P bus for the door modules, which activate the door mirror heaters together with the rear window heater. 

Dan you deserve a Range Rover Degree mate (love-in)

Gazellio wrote:

Dan you deserve a Range Rover Degree mate (love-in)

Yet whenever I apply to work at a LR dealership I get a crappy generic letter back. Contrary to my forum persona, I'm actually a really nice guy in person and own any sales challenge!

I'm sure LR wouldnt want staff in their dealerships that actually know what they're talking about! 

My windows still steam up even with the air-con on auto constant ...

MICK wrote:

My windows still steam up even with the air-con on auto constant ...

And auto recirc?

If there is that much moisture in the air I would question whether you have water ingress somewhere? Or maybe a loose drain tube from the AC making a carpet damp? 

.......or your air con's fecked

.........or you're doing something you shouldn't be.  ... - .- -.




Y. O. L. O.
.

Stop pishin in the car Mick

Many thanks indeed, makes sense