undo,clean up and retighten any of the engine to chassis earth points, it could be a bad earth there.

they norm go down when aircon on dont they? or at leat they did on my hire car saxo in France!

Greasemonkey i agree with tomas it does happen but if doing it with wipers battery could be on the way out

supposed to with air con on

my revs go up when i turn the air con on.

It is to a degree but if it gets worse suddenly then it means your cars lacking electrical output - usually battery/alt. Its the same principal as dimming lights with bass lines...

mine does it if u press window buttons up and they already up, think its normal

Yeah, its the unsmooth flow of current from the alt. Obviousley the alt becomes harder to turn with the more current thats sucked. Its the sudden change from being sucked to being free suddenly make the engine easier to turn/rev and will slightly rev higher. I suppose its like being strangled and then suddely being able to breath again.

Although the wipers dont suck that much? I'd say your battery is failing myself. Current should usually come DIRECT from the battery and if none available or cant give it quick enough then it sucks straight from the alt. Im fairly confident a larger battery with larger CCA should see you better.

the battery might not be strong enough. give it a whirl with a heavier duty one and see what you think.

:| woteva next mate :P

cool............ more revs from some wippers:lol: must try this mod.:P

earth points? :boggle:

Right, i noticed tonight, when electrical equipment that uses short bursts of power, ie things with relays, wipers etc, are on in my car they effect the idle????
When my wipers are on and the cars idling, the wipers come down to their rest position and the revs increase by 200-300 rmp, every time, why is this, batters and alternator are fine????/:boggle: