How do they work? The ones on my Pug 406 normally work well, but in drizzle seem to either be far too keen or downright apathetic. I can't see any obvious moisture detecting electrodes in a cursory inspection.
"malc" wrote in news:6o56h.52254$ snipped-for-privacy@text.news.blueyonder.co.uk:
Dunno about the Pug, but on the Golf it seems to be a light sensitive bit where the mirror is stuck to the screen. A couple of greenfly on the right bit seem to set off the wipers.
malc (malunspamwhite@light_indigo_overthere.co.uk) gurgled happily, sounding much like they were saying :
Look on the outside of the windscreen, just above the mirror. There's a lot of "black-out print" all over the glass, with a square looking a bit different. That's the sensor.
My BMW manual explains how theirs work, as follows:-
"An infra-red beam is directed against the glass through an optical device, and is reflected fully if the w/s is dry. The amount of reflected light is measured by the device. If there are droplets of water on the w/s, the amount of light reflected back is is reduced, since the infra-red beam can escape at the glass surface. In other words, the proportion of reflected light determines the amount of rain striking the w/s."
That's as much as it says, so one is left to assume that any significant reduction in the reflected light triggers the wipers to make a pass. I've noticed that in very fine rain or spray, you can see a small build of of droplets on the w/s before the wiper is triggered, and it starts wiping intermitantly. The delay between wipes is adjustable, so presumably this gives some adjustment of the sensors trigger point. If the rain gets heavy enough though, they change to constant wipe. Mike.
Does anyone know if there is any adjustment possible on the Peugeot system? I have a 306 Meridian with rain-sensitive wipers. As with Malc's 406, they are somewhat erratic at tmes.
My wifes 306 meridian has them, and they work surprisingly well, SWBO has the switch set to auto all the time , no rain, no wipers then depending on the amount of rain/spray they are either on intermittent (delay varies), or full speed! It can be quite strange on a nice sunny day if the car in front washes it's windows, one wipe clears the screen, then back to sleep! I now wish my C5 had them....oh well.. just have to keep looking at the screen and if it gets wet, manually switch on the wipers.
Talking of wash/wipers, I hate it where the wipers automatically start whenever you press the screen wash. I prefer to squirt the water first and then one wipe usually clears the screen instead of having the wipers automatically sweep a minimum of half a dozen times on a dry screen. What I do is locate the relay and the spade connector which operates the wash/wipe function and gently bend the connector to one side and refit the relay. Sometimes in freezing weather when you come to use the washers and discover the spray nozzles are frozen, the last thing you want is the wipers to start their obligatory 6 strokes smearing all the s**te across the screen.
Yes, that annoys me something too... actually it's reminded me, I don't know if the Saab has heated nozzles. I would have thought so, being a Saab and all, but I don't know for sure.
That's just rubbing it in ;) I did drive my brothers Saab for the first time t'other week. I hadn't got a clue what all the switches & gizmoes were for but when the windows started to mist up I just hit a button that said "AUTO" and was very impressed when all the windows suddenly cleared as if by magic. I'd normally be reaching for the chamois in my motor!
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.