Technical battery light on till 3000rpm

[arc]

Ive not yet replaced the alternator (will do that this weekend) just think its kinda odd that when i start the car, the battery light will stay on till the car reaches just under 3000rpm. If i then let it fall below, the light doesnt come back on - unless i turn the car off and back on again.

Just seems a bit weird, i would've thought if it wasnt charging right below 3000rpm, the light would come on whenever the revs were below that..

Also, could a dodgy alternator cause a misfire - was pulling onto a roundabout before and all my power went.. then came back again. Always happens at the worst times eh

 

[J333EVO]

I had the opposite problem where my alternator would only charge below 3000rpm as the light would come on above and not go back out till it dropped to about 2400rpm. I think it's to do the the voltage regulator in the alternator which can be changed on its own, but why bother, if you've removed it, replace the lot.

Aaron.

 

[rallycinq]

It can happen, and I think has with yours. Re the misfire, if the alternator suddenly gives 16 volts or 9 then the injection system is going to get the wrong values all over the place, so yes can cause a misfire.

Cheers

D

 

[The younger modder]

when you say misfire arc do you mean same as i was getting where i would pull onto a roundabout and then it would loose power but still be ticking over and i would have to keep reving it etc giving general abuse and then it suddenly gets power and flies across the roundabout or do you mean for about a second

 

[arc]

it lost power for a second, if that - just didnt pull smoothly as i put my foot down. Like hitting a massive flat spot

 

[paul_treg]

Hi,
Have you checked that the battery and earth connections are all tight and intact, sounds as if one of the earth connectors is loose or something...


Thanks
Paul T

 

[arc]

the earths i know are good - ive taken them all off before and sanded the lot down, with a lil bit of copper grease too.

I'm going to change the alternator this weekend, i'm hoping that'll sort it - but if it doesnt Sie said I can give him my old one and he'll give me my money back. So i've nowt to loose by tring it

I'l recheck all the earth connectors and battery connections whilst i'm at it