alternator light comes on..what next

[awg]

happened to me twice so far, and I replaced the failed unit with a used one that I had on hand the first time, but they can have the brushes replaced for a few $, and that is the most likely problem (although not always, as I found)

I found this online

https://cometbattery.com.au/shop/alt...ngler-tj-4-0l/

($180 locally for a "reman" )..on Ebay "new" units are $275-$500

I couldnt find a local source for a rebuild kit, be about $100 landed from USA

Brushes are worth trying, what you get is just the brushes themselves, which have to be soldered in.

here is a few pics that show how do that, it isnt obvious if you havent done it before

check Youtube for "rebuild Jeep or Denso alternator" (it doesnt show how to solder the brushes...they fit the new piece)

** ( I will edit the pics and further description in later)

[amlav]

I think it cost me around $10 for the new brushes . On mine had to make sure the brushes had the copper wire coming of the brush on the side rather than on top . Best remove the old ones and go hunting on Ebay and compare the pictures with the old brushes . Job it self easy as . It takes longer to remove the alternator than change the brushes .

[eksjay]

I have had the Denso reconditioned twice, and still have it as a spare. They don't make them like that any more.

[awg]

I didnt ask my autolec how much he would charge to rebuild, just purchased the brushes off him, and he checked the slip rings, said they were ok, but imo, marginal

seems one of mine is in some other way faulty, as the brushes were not very worn, and the fault is apparently intermittent, so maybe diodes in rectifier, or bad solder joint>

I do have a couple of spares.

Got my R&R alternator time down from ~120min to 35min

If you havent done it before, not totally obvious how to replace the brushes, compress & push off the nylon slip ring, then desolder the wire at the back of the brush holder and pull out the brush and spring





images

[LuluBelle]

My original alternator died the day I bought the 96 new brushes made it live another 7 years when it died again I got a refurb one for about $160 off a mob in Vic posted to me
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[awg]

Update;

neither of the alternators I replaced the brushes in worked when I installed and tested them in my spare XJ.

I have one tested operational spare, from a spare engine, the other transplanted from the Limited, now in my Sport..both used OEM

As the brushes and slip rings did not seem worn beyond spec anyway, and the PCM regulates, presumably that means the diodes in the rectifier have failed, a "dry" solder joint, or otherwise failed internal wiring.

I do not intend to proceed any further, I cant see that regulators are available as a separate spare part. Just a tip to others.
A reman unit may be the safest bet if you find yourself in this situation

got my R&R alternator time down to 30mins..beat that autolec !
(I am certain they would not charge less than 1hr labor)

tips...turn the mounting bolt around, ( so you dont have to remove electric fan)..grease the mounting flanges...makes lining up the mounting bolt easier

[alexbrown64]

Good write up Tony. I guess when some of these bits get worn, there can be multiple problems.
I bought a 136A Summit TrueSelect Alternator from Summit Racing a few years ago. Only cost $130 US.
Was a good upgrade for my 95. Would not fit my 95 until i swapped out the 95 mounting brackets for 96 brackets. Then it just popped straight in with no mods except a different size belt. Best thing ever, as my bearings were gone in my old alternator and was making a racket.

Cheers,