Battery light comes on at high revs

Hi all hope everyone had a fantastic easter and ate all the chocolate they could find lol. anyway i have a little issue with my battery light. the battery light is coming on between 2500 and 3500 rpm and the battery does not have the power to start the engine after only a few days (yes this is a brand new battery,well was) the vehicle is a gu 98 y61 with a rd28 motor. im thinking it is just the alternator has died but it seems to have anyone i talk to stumped as to why the battery light would be coming on at high revs. i tookm the car to battery world yesterday and all they could tell me was that the battery was charging under load but not at an idle. any help would be much appreciated. thanks

Check the Battery Connections. Remove clean and replace. Might not be connecting properly all the time.

sounds like the brushes in the alternator are worn out.

I could be wrong here but im tipping its something in the brushs losing contact but this should be able to be checked & tested.

As for the not charging at Idle?

A lot of Patrols fitted with RB30's ran a Bosch alternator & thay are renown for low charge rates at Idle so I would not be overly concerned by that fact if your alternator is Bosch of course.

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Originally Posted by patch697

I could be wrong here but im tipping its something in the brushs losing contact but this should be able to be checked & tested.

As for the not charging at Idle?

A lot of Patrols fitted with RB30's ran a Bosch alternator & thay are renown for low charge rates at Idle so I would not be overly concerned by that fact if your alternator is Bosch of course.

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if i replace the alternator will that come with the regulator???
as for the testing well the service at battery world was pretty poor and did not seem to want to help. also the alternator pully bearing sounds as if it is on its way out so if i can kill the 2 birds with one stone so to speak than that would be one piece of good news for the week

Quote:

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Originally Posted by Mrricsta25

if i replace the alternator will that come with the regulator???
as for the testing well the service at battery world was pretty poor and did not seem to want to help. also the alternator pully bearing sounds as if it is on its way out so if i can kill the 2 birds with one stone so to speak than that would be one piece of good news for the week

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Yep it does & given what you said about the bearing noise I'd replace it for sure & if its a Bosch its not that expensive.

I have a TB42 in mine & I converted it from Hitachi to Bosch in under an hr & never looked back.

thanks patch. looks like im off to get a new alternator this week. will let you all know if this fixes the problem. thanks again

Should turn out to be either brushes or a dodgy rectifier diode (altho that usually happens at a lower speed)... Sorry, but I'm not familiar with the 2.8's however most Alternators have an internal Reg these days.

Up to you if you want to get it checked first or just replace it... I'd get it tested... no point buying a new one if it is something else

It sounds like an alternator problem to me as well, what you need to do is check the charge rate at the back of the alternator with the engine running to confirm.

I also agree with the worn brushes theory or it could be a problem with the brushes springs they might have lost their tension or a full of mud.

As stated above, I would check and clean the main battery connections especially the main earth to the block and the smaller one to the alternator (if the 2.8 have one).

So I would use Ashdown and Ingrams for your alternator, they should be in Townesville. I wouldn't be going back to where I got poor service. Local good auto elec would also be able to get one in for you.

Tim

gday gday,
So I got the problem sorted and all is really good now.
So what went wrong?
Well since i asked you all what i should do i will mention that the alternator smelled like it was on fire and you could see sparks inside it when it was running. so i knew i was for sure gunna have to replace it, turns out my mate had one on an engine out the back of his workshop and it was as smooth as. so i managed to wrangle that off him that for a carton of XXXX gold (what a deal!!!!!). any way while pulling out the busted alternator i found that there is a thin black wire that is very hard to see from the underside of the car and well it was not connected!! So i reckon that that is the source of the battery light issue. WOOOO HOOOOOO!!!!!!. Since fitting the XXXX alternator i have had no issues with battery charge levels or that annoying little battery light.
So thanks to everyone for their help!
I would just like to mention too that i believe that the sparks and the burning smell from the alternator are to due me going camping over the easter weekend and driving through several mud holes that had a lot of sand in them and were well used that weekend and never had a chance to settle. This gritty mud got into the alternator and just acted like an abrasive and wore away the protective coating on the coils inside, hense the sparks. Just quickly too i noticed i had to give my radiator a really good hose out cause it got full of mud and the engine was therfore running slightly warm on the way home. but all is good now just gunna get a nice new battery since i dont trust the one that my old alternator flattened. but i will charge the suspect battery and if it does seem to hold charge ok then its just an isolator away from having a duel battery setup. Cool
Hope this can help someone else in the future

Thanks for the reply mate & im glad you got it sorted.

Thanks for the update.

Well you can't complain about the cost.

If you still have the old alternator I recommend that you pull it apart and have a look inside.

This will give you a good understanding of what was happening.

Cheers Rodney

Yep definately sounds like the alternator is a goner, mine blew about 10 months ago melting a battery, batery cables & destroying a $700 batery isolator/management system. Lot's of fun, oh well all new & fixed now. Good luck mate.

Edit,
Sorry mate did'nt see the second page, all good problem sorted good to hear.

Reg in the alternator
Cheers Andrew