This might be an odd question (and I'm still new to the car) but.... Is it possible to turn on the rear screen demister on its own? The reason i ask is than mine only comes on when you turn on the front demister, and as such the fans come on full and AC turns on (which is not much help as my AC is bust anyway). Would be nice to have the rear screen demisting away quietly without a gale blowing around the cabin you see....
Are you sure you turning on the right switch, the rear dimister heats up the screen and not blow it Sent from my VIVO using Tapatalk
I believe so - I have the button as shown here (not my car, but a photo stolen from the internet); (Button on the left with the front screen, rear screen, AC and recirc button) If i press the rear demister nothing happens - no lights on the button at all. However, if i press the front demister, the rear one can then be pressed and will light up and clear the rear window.
I had the air con checked over and the condenser is not kicking in (despite the light coming on) however if the switch is dodgy that might save me a few quid and the air con might work... Think i need to get the switch out and take a look.
Just as an update to this; Firstly, there are two types of switch unit. I found this out after ordering the wrong one as a replacement off eBay. I then ordered the correct one (as stated in the advert) and still received two further wrong ones..... Anyway, having now tested a replacement switch unit (third time lucky from the seller!), the fault is still there with both units, suggesting it is an issue elsewhere. I've since found out (now the colder weather is upon us) that neither my heated mirrors nor my rear demister works. I've checked every fuse in the dash fuse box and glove box with a multimeter, and they are all showing as intact. So I'm stuck now really! Any suggestions are more than welcome....
My R26 had a failed drivers mirror element although the glass was intact. They're dead easy to replace. I guess it's not beyond reason that you could have all three elements failed, especially if the switch and fuse are okay. If you can, get a multimeter across the connections for the mirror element and check you've got 12v when the switch is on. If so, the element or connection is bad. If not, switch not working, not turned on, fuse blown or other wiring problem.
I think that's my next port of call. Forgive me for being dopey here but which setting do i need to set the multimeter to (I've only gone as far as getting a beep to check the connections in the fuses were intact...!)? Also meant to say above - dash fuse box is meant t be engine bay fuse box (that's what you get for not proofreading before posting..!). Also how would i go about checking the relays (aside from swapping them out with working ones - if so; where are they located?). Thanks for this (and sorry for sounding a bit thick).
You want a low voltage dc setting. The beep is continuity - you don't want that setting. Put the leads on a 9v battery to verify. Failing that, a 12v bulb will do (verify it's not blown with the 9volt battery first). Try not to touch the connections together as that may well blow the fuse. Honestly I'd start as near to the element as possible and work backwards. That will be easiest. Are you 100% sure you've got it turned on? I spent ages helping somebody the other day only to find it was the very first suggestion offered that was the culprit lol.
Right I'll give that a go then. Definitely sure it's turned on - although it will only turn on with the front demister (if i press the button i get nothing, however with the front demister on it i am able to light the switch up and turn it off). The AC is screwed but that's another matter (at least i hope it is!).
Well I think that may nearer to the cause, than a failure - I've never heard of a car, nor any of the Renaults I've owed including 2xmk2 Meganes that worked like that you can always just put the heated rear screen on, regardless of anything else you have or have not turned on.
Agreed it shouldn't be acting up like this - having swapped out the switch I feel it must be something a little deeper as its affecting more than one thing i.e. demister and mirrors. Looking through the electrical manuals, i noticed this morning that the function controlled by the Passenger Compartment connection unit (UCH) for the demister also controls the air con (and presumably the mirrors). Given i have suffered with a blocked scuttle drain issue i think i need to take a look at the connectors on this and/or the UCH itself, as if i have problems in here it will more than likely cause these kind of faults. (as a side note, my 'auto' headlights will neither activate nor deactivate, resulting in always on sidelights; another possibility of UCH issues i think...?). I'll take my glove box apart and have a look, and report back what i find.......
ive just read a thread on another forum, on there, a guy who had the same plus his cigarette lighter wouldn't work and his radio wouldn't turn off automatically, turned out it was a 15A fuse marked up radio
Right - had the UCH/BCM out yesterday....and it's bone dry. While this is a relief, I still have the issue. So my next port of call is to remove and recheck each fuse (already done this with the glove box fuses, but checked the engine bay ones in-situ which may not have given true results). Will report back once I've had chance to do this, which may be a while given the wonderful weather we are having...!
