who rebuilds alternators anymore?

Kevin Cozzo

Kevin Cozzo

True Classic
so I'm tearing into my old marelli 55 amp alternator...going to attempt refreshing it, as it never really gave me any problems, and just well worn. I know a little bit about electronical stuff and how it works, but I think I may have lost a part...the diode plate on the big heat sink has a screw on one side holding it down on one side, and the battery+ terminal bolt on the other side. I noticed the +bolt has a plastic isolater where it's held in by the head, inside the alternator, but it makes contact with the heat sink for the diode plate, and the other screw grounds this heat sink. This doesn't make sense to me, seems like the +bolt would be totally isolated from "ground" anyone know what I'm talking about?
Edit: I see now that the heat sink is divided between positive and ground....duh, maybe this will help someone else trying their hand at this. I have a gm cs 130, but it went out on a lifetime warranty, and it had to be special ordered anyways- so what's the point if it's not readily available? also the bracketing was never that great
I wish I could have found a complete rebuild kit for the old Marelli- brushes, bearings stator sleeve, etc
 

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Some regions still have old school rebuilding shops, I know we do locally. While some of the original Marelli replacements parts may not be available (not sure), those shops are really good at finding substitute items that work. Especially things like brushes and bearings. And on units like yours that still worked but are highly worn, that's really all that's needed...along with a good cleaning. They can also rewind it if the old armature has high resistance or broken wires. Or even rewind it to increase the output if desired. I tend to prefer a rebuild from a good shop then buy a remanufactured one, or in some cases even more than a new one.
 
I have a shop near me, but they cant get Marelli parts anymore. They rebuild my Bosch starters and alternators. They just did two for me this year.

Maybe You can find parts on Italy's eBay?
 
Ditto here in SoCal - some small company rebuilds old Bosch’s. My first one failed, second one is still going.
 
well, the funny thing is, I did find new Marellis for dodge chrysler that look like the same bracketing...lol, for around 200 bucks. I did order a new brush set from Matt, almost thought about getting the bearing sizes, and searching for some super high quality ones, as they are easy to find...I will replace the brushes, and clean it's tracks and see where it goes....I'm just really surprised at how simple they really are to rebuild
 
They may have changed their site a bit. I used them a few years ago to rebuild my Bosch alternator. They had everything I needed.
 
JDExSquid said:
They may have changed their site a bit. I used them a few years ago to rebuild my Bosch alternator. They had everything I needed.
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They might, I did not search too extensively. But I thought we were discussing the MM alts; Bosch alts use the same parts for literally millions of applications so their parts are fairly easy to find, where as the MM alts are rather difficult to find parts for. That's what I was looking at. ;)
 
funny, a few years back in a pinch, I took the voltage regulator down to a redneck autoparts store, and even the vo;tage regulator in my Marelli had a bosch part number sure enough, and the guy found me one and saved the day
 
I would figure there are lots of Fiat/Marelli/etc. rebuilt parts floating around in original Fiat labeled bags. Back in the '90s when I was buying old dealer inventories, it seemed like these things were everywhere. In fact, I still have a box full of NOS stuff (but it's buried, not cataloged, etc....so please don't ask for a single piece) that I figured I'd use one day. In fact, out of some interest in the original topic here, earlier this week I bought an alternator/starter testing machine from a NAPA that was retiring theirs (because....everyone just buys a new reman one I guess & all the local shops either don't know how to use the machine or theirs is broken/missing parts). I was a bit more interested in being able to assess the condition/output of alternators, but knowing I have spares that periodically I trip over, having this rig & having that nice book AR sell I might rebuild one .

I suppose we are lucky around here that there is still a decent alternator rebuilder. It's under new ownership where the old owner also did starters, but I had a couple 65amp Bosch (124/2000 TC car type) units rebuilt...fairly cheap, both currently in service, etc.
 
Fiataccompli said:
I suppose we are lucky around here that there is still a decent alternator rebuilder.
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When I was still living in SoCal I noticed the old-school rebuild shops were gradually going away; electrical, radiator, hydraulic, upholstery, etc. The remaining ones had been around forever and did not advertise - all of their business was word of mouth from their long reputation. So if you knew who they were then you were in luck, but if not...well.
I was always amazed at the huge piles of cores stacked up everywhere, must have been tens of thousands of used parts piled up.

Currently I'm living in Vegas and I've noticed there are still a number of those shops around here. That's because the majority of the Vegas population is from Mexico and they bring their craft here with them. They do good work and the prices are reasonable.

So I'm sure it varies a lot depending on where you live.
 
Most of the shops like that around here have become craft beer pubs. I was hoping that market would have been saturated a long time ago, but the services mostly vaporized anyway.
 
So I'm going all stupid on this...Matt had a new brush plate, and upon testing the unit, I found the rectifier to be faulty. Once I got the right part number, I actually found a rectifier on amazon (yeah, it's chinese, but the box says made in Merica! lol) Anyways I'm now looking for very high quality bearings...doing research to find some, and that's fun...now I'm getting an education in friction
 
Speaking of Arizona, I was in

Gen-Star Electric​

6832 N 63rd Ave GlendaleAZ85301
Very old school. They rebuild starters and alternators.
 
Well I found everything that will hopefully make the stock alternator the best it can be...got a new retifier bridge and higher quality bearings on Amazon of all places, and a new brush set from Matt. I had some stuff called "aluminum brightner" from Napa, that made it all pretty again. I was tempted to polish it, but I'll settle for just clean and bright, lol. This was an interesting learning experiance. only thing I didn't replace was the voltage regulator, but heck it's easy to replace if necessary down the road, even with the alt on the car
 
Kevin Cozzo said:
Well I found everything that will hopefully make the stock alternator the best it can be...got a new retifier bridge and higher quality bearings on Amazon of all places, and a new brush set from Matt. I had some stuff called "aluminum brightner" from Napa, that made it all pretty again. I was tempted to polish it, but I'll settle for just clean and bright, lol. This was an interesting learning experiance. only thing I didn't replace was the voltage regulator, but heck it's easy to replace if necessary down the road, even with the alt on the car
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And if you wanted to get extra fancy you can install an adjustable voltage regulator in it. :)

Dave's Volvo Page - Volvo Adjustable Voltage Regulators

Dave's Volvo page. Adjustable Voltage Regulators.
www.prancingmoose.com
 
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