New Generic Alternator Fitted - Should I repair the Original

[SJBS]

Last week, we had some bad luck with the Patrol ('99 4.5 GRX) breaking down while my wife was picking up the kids from school, while I was away for business in another province.
It became apparent very quick that the alternator was the culprit. The regulator and diodes were shot. A quick couple phone calls wasn't looking promising, with no-one having stock. Luckily the local auto electrician had a generic nissan alternator on hand that he could fit within a day to get us going, and at R2800 it seemed not too bad for a new alternator, fitment and fan belts.

I think the new alternator is similar in specs to the original Hitachi of in the region of 70A. See the test sheet of the new alternator below

Generic Alternator Test Results

New Alternator Test Specs.jpg (413.51 KiB) Viewed 3463 times

I still have the old alternator, what is your recommendation:
1) Repair and re-install the original, keep generic as spare
2) Repair and store original as spare
3) Do nothing further, keep generic installed and the broken Hitachi in the garrage for just in case?

If I proceed to repair the Hitachi, where can I obtain the diodes and rectifier and what would the costs be? I would assume that I should replace the bearings as well?

I have taken some pictures of the stripped Hitachi alternator:

Hitachi Alternator showing diodes and rectifiers from side, including connection to stator

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Hitachi Alternator showing rotor assembly

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Hitachi Alternator showing diodes and rectifiers from top

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Hitachi Alternator showing diodes and rectifiers from top/side

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Hitachi Alternator showing diodes and rectifiers from top

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Hitachi Alternator showing part/model numbers Enlarged

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Hitachi Alternator showing part/model numbers

20140824_121056_result.jpg (102.08 KiB) Viewed 3463 times

[marakasmalan]

I bought a pirate a few years back for about R1 100. Served me well. No problems. In fact, provides better current than the Hitachi did. I thought th Hitachi was 90A?

Gave the old one to Peter to "find a good home for" and never thought about it again.

If you are sure the windings and brushes etc is ok, and a new one price upwards of R2000, then replace the reugalator unit and sell it to the next bloke in need. If he funds half of your alternator replacement and alternator repair costs, both of you are in a better position.

To keep it as a spare - That will be unwise, as your new alternator will last a number of years and by the time you start searching for the spare you kept in the garage, you may very well find your son used it for a "science" project.... Rather give it away as is instead of keeping it for a spare.

That's my opinion, in now way any authoritive stamp on the matter.

[Peter Connan]

Your new alternator is 70 A/h (says so on the paper)
The old one was 100 A/h (says so on the label).

I would be worried about a 30% drop in uotput. Ideally, test your maximum consumption by using a clamp meter and running all possible ancilliaries at the same time (brights, air con, dual battery charging system, etc). If your vehicle can draw more than 90A/h, I would replace the pirate.

Whether the replacement for the replacement is another pirate of higher output, or a repair of the original, depends on cost...

[AndriesS]

I'm with Peter on this, Lights, driving+fog lights is 20A, add a set of spot (halogen) and you have another 10 A, aircon and radiator fan another 10 A, electronics, fuel pump etc , 5-10A . Ad another 10A for all the charging of GPS, phones , etc . You could easily run out of power. At night, switch all on max, aircon, brights, fans - lift wipers and put them on, dim speedo lights and your alternator light might just glow in the dark. if you intent to throw the old one out , at least take good measurements of the mounting . Makes life easier if you need to find a replacement .

[Tinus lotz]

I agree with Piet a lot of energy goes into losses by charging batteries running spots and brights etc .....last thing you want is to be in middle of namib and alternator works to hard and blows up ......graham keeps those alternators in stock if you want to part with the old one but I am sure the plugs are different so rather measure and make sure

[ricster]

I replaced my Hitachi alternator with a .........(don't recall the name)....about 3 years ago, which is probably a chinese copy, but it takes a standard Bosch regulator, which is available anywhere anytime. I replaced it with a 100A/h as my Hitachi was only a 60A/h !!!
But my old school diesel doesn't have much in the way of electronics, but once you start adding extras like fridges and amplifiers and 110W KC spots and extra power points to run almost everything the wife could possibly need.... you need the bigger amp alternator..... Just my opinion too

[marakasmalan]

Ad another 10A for all the charging of GPS, phones , etc

Phew! What phone you have? Nokia 2110 with the optional 3kg long life battery pack? I think the fuse on the cigarette lighter is 5Amps?

Even so, if you use two outlets, to draw 10 amp you'll require a total of equipment. Unlikely that you will be able to do so over an extended period of time.

Moreover, intersting is that I have driven my patrol for weeks on end with the revs never over 1750 - and this means the alternator does not push serious amps - without any issues. My electronics are limited, though.

But, the odd occassion where all the equipment (especially the spots) will be working it is likely the engine will be running at higher revs pushing more amps. Unlikely you will run out of power, based on the table from Andries and the statistical odds of all working at the same time. Should they all work at the same time, the source is limited - your fridge wont't cool as much, the spots will fade and the battery will be drained. The ECU and other stuff is designed to handle voltage drops, no problem there.

Looking from this angle, is this a problem you need to anticipate pro-actively or can you wait and see more?

[marakasmalan]

Ad another 10A for all the charging of GPS, phones , etc

Phew! What phone you have? Nokia 2110 with the optional 3kg long life battery pack? I think the fuse on the cigarette lighter is 5Amps?

Even so, if you use two outlets, to draw 10 amp you'll require serious Watts from the equipment, unless you have a 12V kettle etc you will struggle to achieve that. Moreover, unlikely that you will be able to do so over an extended period of time.

Moreover, intersting is that I have driven my patrol for weeks on end with the revs never over 1750 - and this means the alternator does not push serious amps - without any issues. My electronics are limited, though.

But, the odd occassion where all the equipment (especially the spots) will be working it is likely the engine will be running at higher revs pushing more amps. Unlikely you will run out of power, based on the table from Andries and the statistical odds of all working at the same time. Should they all work at the same time, the source is limited - your fridge wont't cool as much, the spots will fade and the battery will be drained. The ECU and other stuff is designed to handle voltage drops, no problem there. Once these symptoms are observed, switch a few luxuries off and no problem. Get home, replace the alternator.

Looking from this angle, is this a problem you need to anticipate pro-actively or can you wait and see more?

[SJBS]

Thanks a lot/Dankie/Kealeboga

I did not even notice the 100A on the Hitachi.

My car is equipped with wiring to power a fridge, thus will have to keep that in mind when measuring. Any suggestions where to obtain the diodes and regulator for the Hitachi? I see the other posts talking about Sparxx ( thus will require courier because they are in Capetown while I'm once a week in JHB/PTA.)

Thanks

[AndriesS]

I know I posted worst case, but worst case normally happens at night in the rain, battery is not 100%, family steaming up the windows on a remote road or road dangerously close to an informal settlement known for their unfriendly behaviour when you really do not want to switch off the lights, the wipers , the aircon and fans etc and you seriously do not want to run out of power and drain the battery slowly. As for the lighter you'll be surprised how many aftermarket, crossovers etc are wired in there and many shops just up the amps on the fuse. You also don't know what the PO and current owner did, did the change the 55W H4's for 90/100W and did they change the fog lights to 100W and those big spots are they running 100W cause just those 6 at 100W is nearly 60A

For my own piece of mind I'll even go higher than the factory unit. I've done so on many cars where I had troubles with alternators and regulators packing up on a regular basis ( every 2nd year or so).


Sparxx is a big electrical spares shop and I'm sure CT has them as well, maybe Frans or GMan can guide here. If you don't come right and only Sparxx can assist then there is a couple of chaps in PTA that can help (including me). another crowd is Breno electrical (Boksburg and Joburg) , Motolek franchise that gives very good service and I got my patrol start from them.