My car is a W203 C-class Estate (270 CDI Elegance SE). As part of its equipment, it has heated door mirrors. Now, my passenger side mirror seems to work in that it will demist in misty conditions, but the driver's side didn't work. So, I duly ordered a new mirror glass including the heating element.
I took off the old glass/element, and found it wasn't connected - well it was, only one connection (brown/grey) instead of two. Also I found a 4-terminal connector but one of these, the brown/grey, had another wire coming out the back of the block and terminated with a small female spade (which was connected to the mirror glass/element).
I looked up online and found a wiring diagram, which revealed the 2 connectors for the heating element are the brown/grey and red/black. So I added a little wire from the 4-way block to the existing glass/element. However, during testing I put a multimeter on the terminals, expecting 12V at some stage, but I got readings of nothing (0V). I tried with the ignition on, engine running, front & rear screen demister on, etc.
So I took off the passenger door mirror too (which I know does demist) and it too gave 0V readings. But it works!! So the question is.....
When does the glass element work?
I guess I can wait for the next misty/cold evening to see if my added wire has fixed the issue, but I was a bit disappointed that my multimeter couldn't check the wiring was okay etc.
I've also checked the relevant fuses, none were blown etc.
I took off the old glass/element, and found it wasn't connected - well it was, only one connection (brown/grey) instead of two. Also I found a 4-terminal connector but one of these, the brown/grey, had another wire coming out the back of the block and terminated with a small female spade (which was connected to the mirror glass/element).
I looked up online and found a wiring diagram, which revealed the 2 connectors for the heating element are the brown/grey and red/black. So I added a little wire from the 4-way block to the existing glass/element. However, during testing I put a multimeter on the terminals, expecting 12V at some stage, but I got readings of nothing (0V). I tried with the ignition on, engine running, front & rear screen demister on, etc.
So I took off the passenger door mirror too (which I know does demist) and it too gave 0V readings. But it works!! So the question is.....
When does the glass element work?
I guess I can wait for the next misty/cold evening to see if my added wire has fixed the issue, but I was a bit disappointed that my multimeter couldn't check the wiring was okay etc.
I've also checked the relevant fuses, none were blown etc.