Hofmiester 10 Posted December 16, 2012 Hi, Only just realised this weekend that my rear window defrost isn't working, the car is garaged all the time since I bought it in October. I'm going to start digging around with the multimeter but what would really he is knowing how it should behave. Currently, when I press the switch on the dash, nothing happens.....no change of colour or confirmation that it is on like in modern cars. Should the switch do anything when pressed? Cheers Ron Quote Share this post Link to post Share on other sites
tony_ack 0 Posted December 16, 2012 Switch it on and the switch should illuminate with an orange ring, like the front fogs. Quote Share this post Link to post Share on other sites
Hofmiester 10 Posted December 16, 2012 Thanks a lot, looks like the power is not even getting as far as the switch, which probably makes finding the problem easier.....I hope :) Quote Share this post Link to post Share on other sites
Supercharged 2 Posted December 16, 2012 Check fuses first! Quote Share this post Link to post Share on other sites
Hofmiester 10 Posted December 16, 2012 Check fuses first! Sage advice! Quote Share this post Link to post Share on other sites
Supercharged 2 Posted December 16, 2012 Mirror heaters should be on the same circuit - these working? Quote Share this post Link to post Share on other sites
Jim 2 Posted December 16, 2012 Could be that the switch itself is just faulty too.. pretty sure I've replaced a heated window switch on one of my cars over the years as it simply never turned on when the switch was pressed! Quote Share this post Link to post Share on other sites
Supercharged 2 Posted December 16, 2012 You're right Jim, I think they maybe fail more than other switches because of the increased current going through them. Quote Share this post Link to post Share on other sites
Hofmiester 10 Posted December 16, 2012 Good advice guys, this forum is a gem! I'll check the switch and fuse first, any ideas on what the input output is like on the switch? I imagine it has power from dash lights and then either power directly to the switch heading off to the elements for heating, or it heads off to trigger a relay. Just wondering how complex the system is as it could also be a relay if there is one? Cheers Ron Quote Share this post Link to post Share on other sites
Stonejag 10 Posted December 16, 2012 If the switch has ever been taken apart it may have been put back together wrong. If you pull on the button then it'll come free (don't lose the two small springs!) Then you'll see a plastic toggle piece which can flip up or down. This needs to be set right when the switch is reassembled or it just won't work, even though nothing looks wrong! Try taking the front piece off, flipping this toggle the other way and pushing the button back together, it may start working :) Quote Share this post Link to post Share on other sites
matttromans 0 Posted December 16, 2012 Sorry for the hijack, but my heated mirrors have never worked, suggestions gratefully received! Quote Share this post Link to post Share on other sites
Portent 0 Posted December 17, 2012 ^^ Do you mean they don't move or they don't heat up? If movement is the problem then the mirror switch often oxidises inside and needs cleaning. If you have no heat then it could be the connection to the mirror itself - prise the glass off and get a volt meter across the two wires that go into the back of the glass and see if there is any power reaching them. Quote Share this post Link to post Share on other sites
Hofmiester 10 Posted December 17, 2012 ^^ Do you mean they don't move or they don't heat up? If movement is the problem then the mirror switch often oxidises inside and needs cleaning I had this with mine, no movement on passenger side. Kept working the switch and it came back to life, likely to be because I repeatedly moved the switch and wore through the oxidisation. Will remove and clean when I have a sec Good call on the switch having possibly been dismantled in the past, will let you guys know how I get on Quote Share this post Link to post Share on other sites
matttromans 0 Posted December 17, 2012 ^^ Do you mean they don't move or they don't heat up? If movement is the problem then the mirror switch often oxidises inside and needs cleaning I had this with mine, no movement on passenger side. Kept working the switch and it came back to life, likely to be because I repeatedly moved the switch and wore through the oxidisation. Will remove and clean when I have a sec Good call on the switch having possibly been dismantled in the past, will let you guys know how I get on Cheers both - they move, somewhat erratically, but they move. They don't seem to heat though - will get the multimeter out and see whats what... Quote Share this post Link to post Share on other sites