A207 Heated Rear Window

[alldar]

How can I check the heated rear window and heated mirrors are working properly.....they don't seem to clear the glass of droplets. On the HRW, I have checked voltage on heater strands using a multimeter and grounded to door latch - zero when not on, 0.6v when switched on?...would have expected 12v.....anybody any ideas?

 

[Ted]

If the elementss are printed on the screen and you can get to them with a voltmeter, put one probe on earth and the other in the middle of each element.

6 volts means it is working as it should
0 volts means there is a break between the supply and the point you are measuring
12 volts means there is a break between the point you are measuring and earth.

I prefer a testlight. Much more visual.

 

[alldar]

Thanks Ted, I'll have another go and see what I get.

 

[Dec]

The temperature of the mirror glass needs to be below about 15° in orderfor the mirror to heat up.

If you put a cup of boiling water under the rear window on a cold morning then the window should mist up which should then start to clear within a minute or less when demister is switched on, engine might need to be running.

Dec

 

[alldar]

When checked out, now seems to be working ok.....may be due to temp getting colder....low temp limit before fully functional??

 

[whitenemesis]

Only on the door mirrors, which come on automatically at temps below 15c. The rear screen heater should come on whenever the switch is pressed, IGN on.