windscreen wiper strangeness !!

HDI · Unread post by **HDI** » 16 Mar 2010, 21:47

On the way home tonight an odd fault happened !!
Went to use the windscreen wipers and all I got was the washers !! The wipers stayed parked and the battery light came on !
The headlight washers also worked ok.
I also noticed that the battery warning light brightens when I try to use the wipers.
However , although I haven't actually checked yet , I think the alternator is still charging.
Is the battery warning light used to indicate other faults ?

Unread post by **xantia_v6** » 16 Mar 2010, 22:00

It sounds like a wiring fault, or if you are lucky a blown fuse.

HDI · Unread post by **HDI** » 16 Mar 2010, 22:07

Well I'm hoping for some tell tale evidence when I investigate in the morning.

HDI · Unread post by **HDI** » 17 Mar 2010, 20:27

Well , simple solution to this fortunately , fuse number 30 had blown but it serves the electric windows !! I did notice the windows didn't work this morning before I discovered the blown fuse.
Strange the wipers didn't work , even though they have their own fuse , and the battery light was on ?
So , does the battery light also somehow warn of a blown fuse ?

Unread post by **xantia_v6** » 17 Mar 2010, 21:06

In most cars the charging warning light is connected between an internal rectifier in the alternator and some circuit that is live when the ignition is switched on. Normally the light is on when the ignition is on, but the alternator is not producing internal voltage.
If the fuse that feeds the circuit that the bulb is connected to, blows, then you can get reverse feed through the bulb, trying to power whatever it is normally fed through the fuse.
the diagnosis was a lucky guess on my part.