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Alternator

Posted: Tue Mar 22, 2005 7:57 pm
by Tiny
Any one got a wiring diagram for a "90 GQ td42 ...I think my alternator is stuffed so will pull off and chack, but want to cover all bases

Cheers

Tiny

Posted: Wed Mar 23, 2005 9:21 am
by BigMav
what is the problem you are having. not charging? or battery not holding charge?

The alternator is piss easy to rebuild with all new components. Replacement cost for a new one is bloody unbelievable. I got mine rewound to give a higher output and replaced all bearings, rectifier plate, regulator and brushes for under 200 from memory. I sandblasted it then put all back together. Looks just like new and all the guts of it are new. Replacement cost was about $1200 trade I think for a new one.

Posted: Wed Mar 23, 2005 9:24 am
by Tiny
BigMav wrote:what is the problem you are having. not charging? or battery not holding charge?

The alternator is piss easy to rebuild with all new components. Replacement cost for a new one is bloody unbelievable. I got mine rewound to give a higher output and replaced all bearings, rectifier plate, regulator and brushes for under 200 from memory. I sandblasted it then put all back together. Looks just like new and all the guts of it are new. Replacement cost was about $1200 trade I think for a new one.


Alternator is not charging. got a pretty good hit of muddy water so mabe the windings are dirty?? don't want to go new, but what kind of price from wreckes or just go rebuild....what time to rebuild?

Posted: Wed Mar 23, 2005 9:39 am
by BigMav
When I did mine all the wreckers up here had a good idea of what the genuine alternators were going for and were still charging a fortune for alternators that weren't in much better nick that I already had. Go to an auto electrical wholesaler such as Ashdowns (don't know if they are in sydney) for the electrical bits (rectifier plate, regulator, brushes) and cbc or something similar for the bearings. (you'll need the bearing numbers most likely) In your gregorys manual they explain how to test the rectifier and regulator with a multimeter, usually the rectifier is ok. Regulator's tend to stuff up more regularly and brushes go all the time especially if there is a fair bit of crap in there.

In your case I would first pull the alternator out and take it to an auto eleccy and ask him to put it on the test bench. They shouldn't charge anything for this as it takes only seconds to do, from there he can tell you what the problem with the alternator is if anything. Good luck with it.

Posted: Wed Mar 23, 2005 9:40 am
by BigMav
by the way it doesn't matter if the windings get dirty. water however can damage stuff in there. ;)

Posted: Wed Mar 23, 2005 9:48 am
by bogged
mine died last week on way back from murray sunset (diesel auto).

New brushes and it was working happily, the dude said it already had the big diode pack in it (ANYONE KNOW WHAT THAT MEANS?)... Cost me $140 in Bendigo. Dont know if its cheap or not, but I had no choice. but happy with the cost, it got me going again.

Posted: Wed Mar 23, 2005 10:10 am
by Tiny
bogged wrote:mine died last week on way back from murray sunset (diesel auto).

New brushes and it was working happily, the dude said it already had the big diode pack in it (ANYONE KNOW WHAT THAT MEANS?)... Cost me $140 in Bendigo. Dont know if its cheap or not, but I had no choice. but happy with the cost, it got me going again.


I am expecting it to be the regulator and posibaly diode pack, but maybe not as it isn't draining the batery.

Definatly isn't charging, so have it down at the auto sparky now

Posted: Wed Mar 23, 2005 10:19 am
by bogged
Tiny wrote:
bogged wrote:mine died last week on way back from murray sunset (diesel auto).

New brushes and it was working happily, the dude said it already had the big diode pack in it (ANYONE KNOW WHAT THAT MEANS?)... Cost me $140 in Bendigo. Dont know if its cheap or not, but I had no choice. but happy with the cost, it got me going again.


I am expecting it to be the regulator and posibaly diode pack, but maybe not as it isn't draining the batery.

Definatly isn't charging, so have it down at the auto sparky now

Mine drained BOTH batteries down till the car physically stopped ....

Posted: Wed Mar 23, 2005 10:29 am
by Tiny
bogged wrote:
Tiny wrote:
bogged wrote:mine died last week on way back from murray sunset (diesel auto).

New brushes and it was working happily, the dude said it already had the big diode pack in it (ANYONE KNOW WHAT THAT MEANS?)... Cost me $140 in Bendigo. Dont know if its cheap or not, but I had no choice. but happy with the cost, it got me going again.


I am expecting it to be the regulator and posibaly diode pack, but maybe not as it isn't draining the batery.

Definatly isn't charging, so have it down at the auto sparky now

Mine drained BOTH batteries down till the car physically stopped ....


yes, that would be right if the diode pack had failed as they generaly will drag charge from the battery.........thats why I am thinking regulator only :?

Posted: Wed Mar 23, 2005 10:51 am
by BigMav
For anyone that doesn't know diode pack is the same as rectifier. Also when i got my rectifier from ashdowns there was only one type available from them so don't know what the "big diode pack" is all about. Brushes are only about 10 bucks and ten minutes to solder them in so if you were charged 140 bucks for that you were taken for a ride unfortunately.

Posted: Wed Mar 23, 2005 11:00 am
by bogged
BigMav wrote:. Brushes are only about 10 bucks and ten minutes to solder them in so if you were charged 140 bucks for that you were taken for a ride unfortunately.

broke down ~180klms nth of Bendigo (little toilet called Nullawil) in a town that consisted of a disused Wheat Sylo, 2 speed cameras, 2 mobile cops, 4 boarded up shops and a farm house, 45 degrees, not a tree within range of a Space Shuttle...

managed to score a ride off a chick in the only farm house for 293048230948230948 yrs, bought new battery, got me to bendigo, got fixed, didnt care in the end how much it cost, it was cheaper than $750 for a new one...

Posted: Thu Mar 24, 2005 3:11 pm
by bazzle
Often when muddy water gets in the brushes either stick or wear real quick giving no contact with slip rings.
To check run a hose thru whilst tapping alt.
If it comes good all you need to do is clean it out and maybe replace brshes and bearings.

New ones (and with higher output ) available over nite from

http://www.aea.com.au/

Bazzle

Posted: Fri Mar 25, 2005 4:16 pm
by Woop
I dont think its the size of the Diode Pack Bruce, but earlier versions had very fragile diodes 'moulded' into the heatsink. Later versions have conventional diodes pressed into the heatsink. These are much easier to replace than the earlier type.

Nick