Fiat Dino 2400 Coupe alternator

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doublegarage
Posts: 212
Joined: Thu Nov 14, 2013 4:22 am
Dino: Fiat Dino 2.4 Coupe
Location: California, USA

Fiat Dino 2400 Coupe alternator

Post by doublegarage »

During my early days with this Dino (early 2012) I had a lot of electrical troubles - and at the time wondered whether many of them were caused by a bad alternator or voltage regulator. I was in the mood to fix all problems forever, so I did some research and found that a later Magneti Marelli alternator with internal voltage regulator would fit the car. These also have increased output (55amp) over the stock alternator

I purchased one of these and made the necessary wiring changes - it was pretty easy in the end - disconnect one wire and change the charge-warning-lamp relay from Normally-Closed (NC) to Normally-Open type. But - fitting the alternator was not so easy. The increased diameter of the alternator-body makes it surprisingly difficult to get into position. I did it all from above but on the 2400 Coupe at least, access from below is also good because the alternator hangs off one corner of the engine. Once it was finally in there (having removed both oil-pressure switches from the pump body, and the horn compressor...) it never really seemed to fit properly. The increased bulk means it won't "swing inwards" towards the engine block far enough for the correct fan-belt to be fitted. I had to go up a half size, but it was really always a little loose, and likely to get looser. Also the way the top adjusted bolt tightened just didn't seem right - I can't explain this properly, but something somewhere was slightly misaligned.

I guess I would summarize it by saying...the 55amp alternators will fit, but not very well :-)

And that has always bothered me - so I had the original (external-regulator) alternator re-built - and today I put that back in the car. So now I have gone back to external regulator - so swapped back to the NC relay and reconnected terminal 67 on the regulator to 67 on the alternator. I used one of the newer solid-state external regulators but cut a big hole in the bottom of the original "black-box" regulator so that it looks right. That goes nicely with the Volvo ignition module hiding inside my Dinoplex box.

The old electrical problems were all traceable to bad grounds at the fuel pump and elsewhere - i.e. now I don't think the alternator was my original problem, so I'm happy to have this one back in there.

I couldn't test it unfortunately because I sent out the oil-feed lines for the aux airpump to be rebuilt - but...should be ok...

-Richard
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