F355 alternator rebuild update, with part numbers.

Yes...mine idled at 1150 and rough. ..choppy. rebuild =normal idle....and alternator light goes out at startup after the rebuild. Twice. 14 on the volt meter from the rear of the car

 

A big hint for alternator removal: Save yourself time and frustration by knowing that the alternator has to be unscrewed then ROTATED to get it out. Otherwise, it just bumps and clunks against other parts and seems like it will never come out.

Unscrew it, rotate it a bit (clockwise? cant remember) and then she will come out.

 

This does not make sense. Unscrew from what? What unscrews from what? Rotated in which direction?

 

I found that when the alternator is being removed from underneath the car (after the bolt(s) are removed), I had to rotate it, or it just would clunk into other parts and be impossible to remove. Just trying to save someone a few minutes of frustration as they say "Jeez, how the hell do I pull this thing out of here?!!?!?! It's stuck!"

Not sure if it was clockwise or not.

 

Denso part number is 126000-0400, I got one on ebay as my new 355 purchase 2 weeks ago did not make it home! Well not in one stint, it did it in relay form. It was very Italian, everything started of just fine, then the battery light started to flicker, then all the warning lights, Air bag, ABS, Check engine, Suspension light all took turns in coming on, like a disco, then a loss of power then it needed a rest!!

Anyway I took a booster pack as I expected some kind of electrical trauma, which is what I got.

I replaced the regulator with a genuine Denso part, and the rectifier with the Regitar RN-02, the brushes where like new and the resistance to both terminals was the same, I repacked the lube in the bearings, and put it back on the car, battery was charged and tested over 100CCA over spec good news, and replaced the heat shields on both sides with Exotic car gear ones, they seem to offer a lot of protection to the back of the alternator.

The Denso unit also looks better quality than the unit that came out, I had a receipt that showed it had been repaired twice before, the quality of the brown Bakalite just didn't look as good as the new part. Anyway a couple of hundred miles later about 400 and not a single light or flicker or anything, so try to get a genuine regulator and that should help with your woes.

 

Great info, thank you for sharing.

 

Yes kinda like a puzzle
Just pay attention when you take it out.

 

Anyone know why the link to the place to buy them tries to download apps onto my computer....I need to get these two parts but can't seem to find anyone that sells them...

 

Holcomb site has been hacked, or they are no longer in business and someone bought the web address.
No matter, from the latest posts, you want an oem Denso regulator. Ebay listings have them https://www.ebay.com/itm/DENSO-REGULATOR-126000-0400/302891204478?epid=193242611&hash=item4685b8ff7e:g:k7MAAOSwPxVbWsUF
Be careful, lots of sellers are offering fake Chinese ones, this lister claims his are oem.

Then you need an Regitar RN-10 This seller appears to have them....confirm the part number though
https://www.ebay.com/itm/Ferrari-F355-355-Alternator-Rectifier-Regulator/223109686375?hash=item33f25fa467:g:CaMAAOSwj~9behnG

 

JM, my name is Marcelo , I am from Brazil, I have F355 gts 1997 . I replaced the recifiers and regitar regulator, and the battery lamp turns on for 5 seconds , and turns off for 1 second. With voltmeter I see 12.3 volts when the lamp is on, and 14,6 when the lamp is on. What do you think is the problem? Can you help?


Sent from my iPhone using FerrariChat.com mobile app

 

Two things to make sure of on the 355:
1) Make sure you have a proper grounding cable from the alternator to the chassis. Ferrari added one late in production and a 1997 did not have one, unless the dealer added it later. Check the online parts catalogs, which will show where it should go. (you can make your own easily with some 12ga wire and ring terminals)
2) The positive battery cable has a red wire, which is molded into the clamp. This wire you must inspect carefully. It is very easily broken when changing the battery, yet from casual inspection, looks fine, and appears to be making connection. If it is intermittent or disconnected, it can cause the battery lamp to illuminate. Remake the connection with a ring terminal if your is bad.

I had a good friend mess with a battery light for over a year, replacing the alternator twice and battery once before finding the red wire at the positive battery clamp was the problem all along. It was broken, but appeared fine. Once they inspected closely, the technician saw the break in the wire were it met the battery clamp.

Finally, it is not out of the question, that you could have an out of box failure of the Regitar regulator. Try to source a factory Nippondenso if you can.

 

The alternator on my '95 355 just failed at 66,000 miles. Found repair parts on Ebay today and ordered the one that includes the rectifier and brushes along with the regulator. $46.49 Shipped. Also bought a reman alternator on Ebay, from the US, to have on hand if the fix parts fail. I chased down some of the helpful links from years ago and none of them opened. Hope this helps..

maniacelectricmotors (5,203 )
Hi, Look at these different Kits for Ferrari alternator 101211-7540
https://www.ebay.com/itm/285042055497
https://www.ebay.com/itm/275543738079
and
https://www.ebay.com/itm/285042112141

 

I would only buy the genuine Denso parts if they are still available. All the Chinese stuff is iffy in quality. I'm quite certain the "maniac" branded stuff is from China.
I see the Denso regulator is still available online.

 

If you can point me that Denso web address I'd appreciate it. I did tons of Google searches and did not find it. Thanks

 

I'd also like to order alternator rebuild parts and would like the links if anyone has them. The Chinese parts are strand you on the side of the road garbage and so are the "reman" alternators. All aboard the fail train.

 

There are Ebay sellers with listings claiming Denso factory parts.
https://www.ebay.com/itm/275319253101?hash=item401a4e686d:g:ZJwAAOSwEjpih7mG&amdata=enc:AQAHAAAAoHvkKHgGnyZb0GjVJlWhLcDDhYpj9hDzOu9mBty+HsFoLXlhMx4XfHJ6W8Gth4w+5xwb3S04qoEAPAeXQ5J3Mf9YCCW8f8L8F9Sg+T8DGHEul90o7p3WYAtb9NO6zHtQIfUb9J08/eSX944h/G6w2Xf4+fdZFJZl4OAe4MCDFxe9J37aXiWzZ7unETcQW8rHo3J3rZG9MW2pATJ6ubJkO70=|tkp:Bk9SR_TNmMCRYQ

Amazon:
https://www.amazon.com/Nippondenso-Regulator-126000-0400-Compatible-1-6L-3-0L/dp/B0B1PZ752L

 

Thank you kindly.

 

When these alternators fail do they make noise or just quit charging? Something is making a rattling noise and I was hoping alternator, maybe the water pump but hope not the engine.

 

Depends on whether the failure is mechanical or electric. Alternators have bearings...



Rattling sounds a bit more serious. Can you use a long pipe as a listening device to isolate the sound (without getting the pipe stuck in the belt ).

Electrically.... Are you getting a battery/alternator warning light?

 

I don't have a production 355. I have a 355 powered P4 replica which does not have light. Image Unavailable, Please Login

 

How many wires do you have on your alternator's small connector?

Anyway, isolate the noise first. If your car is running normally, then its unlikely to be an alternator electrical issue.

 

They usually just stop charging (just had this happen to mine). However, there are bearings in it that can go bad, so could still be there. I would try to isolate the noise location, it could be any of the accessories or the alternator belt tensioner bearing. Could also be the timing belt tensioner bearings.

 

Noises are usually very easy to diagnose because they, you know, make noise.

 

The key word being usually. My rattling (what I thought) gearbox turned out to be a spark plug and fuel injector issue causing an imbalance.

Maybe a video of the rattle would help us identify the issue?

 

Regitar will sell you the part directly. They are nice to work with.
[email protected] - Eric seems to specialize in alternator parts. Very helpful.

I'm having trouble finding out if these parts will work in both ND alternators. I have the 155785, 101211-5071. It seems the threads focus on the later model 156235.

Eric at Regitar looked over this thread and is sending me the RN-10, VRH2005-18a, and the BH-ND10 "brushes".

I will report back if I have any luck with my early model alt.