I trying to help friend locate a source to obtain diodes for his Marinelli alternator out of his 1969 365GT 2+2.
Any direction would be of great help.
Peter Perry
Looking for Diodes for 365GT 2+2 alternator
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- Posts: 18
- Joined: Sun Oct 05, 2008 10:05 pm
- Location: Rensselaer NY
Looking for Diodes for 365GT 2+2 alternator
1972 911T Coupe
1965 230SL Light Ivory
1959 MGA driver
1960 MGA project
1971 Caprice
1970 280SE Coupe
1975 Maserati Bora gone and greatly missed
1964 Morgan 4/4GT
1969 Ferrari 365GT 2+2 12223 SOLD
1965 230SL Light Ivory
1959 MGA driver
1960 MGA project
1971 Caprice
1970 280SE Coupe
1975 Maserati Bora gone and greatly missed
1964 Morgan 4/4GT
1969 Ferrari 365GT 2+2 12223 SOLD
Re: Looking for Diodes for 365GT 2+2 alternator
Hi Perry,
I've no direct experience, but the book, Ferrari Tuning Tips and Maintenance Techniques by Apen and Roush recommends replacing bad Marelli alternator diods with a diode kit from Motorola Automotive Products. I don't know where to find the kits. They discuss it as if they are readily available, but I don't know that.
Apen and Roush say, "Replace diodes with red markings with Motorola part no. 2-1: replace those with black markings with Motorola part no. 2-2. These are 25 ampere 100V diodes that must be pressed in and out. Be certain you have the proper equipment -- a small press -- to handle the job. Use caution when pressing the diode in. Do not apply pressure to the lead or glass seal area. Solder the leads carefully and quickly to the diode lead. Trim lead to length if necessary. Check the diodes to be sure the test light functions properly."
The above book is worth having for anyone owning a vintage V12 Ferrari. It describes lots of interchangeable and equivalent repair parts throughout. Available often on EBay.
Good Luck!
Tom Kizer
I've no direct experience, but the book, Ferrari Tuning Tips and Maintenance Techniques by Apen and Roush recommends replacing bad Marelli alternator diods with a diode kit from Motorola Automotive Products. I don't know where to find the kits. They discuss it as if they are readily available, but I don't know that.
Apen and Roush say, "Replace diodes with red markings with Motorola part no. 2-1: replace those with black markings with Motorola part no. 2-2. These are 25 ampere 100V diodes that must be pressed in and out. Be certain you have the proper equipment -- a small press -- to handle the job. Use caution when pressing the diode in. Do not apply pressure to the lead or glass seal area. Solder the leads carefully and quickly to the diode lead. Trim lead to length if necessary. Check the diodes to be sure the test light functions properly."
The above book is worth having for anyone owning a vintage V12 Ferrari. It describes lots of interchangeable and equivalent repair parts throughout. Available often on EBay.
Good Luck!
Tom Kizer
So many sidewalk cafés - so little time left.
1969 365 GT 2+2 S/N 12293 (Gone but not forgotten)
1967 230 SL 4-spd (Currently on CPR)
1969 365 GT 2+2 S/N 12293 (Gone but not forgotten)
1967 230 SL 4-spd (Currently on CPR)
Re: Looking for Diodes for 365GT 2+2 alternator
Perry, Motorola has been out of the automotive alternator business and the semiconductor (diodes) business for some time now. The style of diodes has also changed from the pressfit type as your Marelli is, to soldered assemblies, and therefore the old pressfit diodes have not been in production by any noted source for some time now. Many of the remaining alternator rebuilders have either a stockpile of the old pressfits or they have some unique offshore secret source for them. In any event I would suggest that you contact one of the current rebuilders, such as Bosch people or Prestolite and see if they will either sell you some diodes or have them rebuild and test it for you. Note, that the Marelli alternators and starters were made under Bosch license back then, and the rebuilders usually have no problem rebuilding Marelli electeics. Jim
Re: Looking for Diodes for 365GT 2+2 alternator
Jim,
That's what I love about TomYang.net. There's always someone who can provide an update to the technologies and techniques of the past. The third edition of the Apen/Roush book was in 1975 and the 22nd printing was in 1989. I don't know if that was the last.
I think I'm going to print your post and insert it into my book as an update for when I eventually need it. Thanks for the info.
Perry, I'm sorry for providing obsolete information.
Tom Kizer
That's what I love about TomYang.net. There's always someone who can provide an update to the technologies and techniques of the past. The third edition of the Apen/Roush book was in 1975 and the 22nd printing was in 1989. I don't know if that was the last.
I think I'm going to print your post and insert it into my book as an update for when I eventually need it. Thanks for the info.
Perry, I'm sorry for providing obsolete information.
Tom Kizer
So many sidewalk cafés - so little time left.
1969 365 GT 2+2 S/N 12293 (Gone but not forgotten)
1967 230 SL 4-spd (Currently on CPR)
1969 365 GT 2+2 S/N 12293 (Gone but not forgotten)
1967 230 SL 4-spd (Currently on CPR)
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- Posts: 1206
- Joined: Thu Jan 22, 2004 5:53 pm
Re: Looking for Diodes for 365GT 2+2 alternator
Marinelli- Detroit Lions disaster!
Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
Re: Looking for Diodes for 365GT 2+2 alternator
I was able to get them from a local alternator shop and they were cheap. Just bring a sample with you. I believe your alternators should be 55 amp. They also had brushes that were close and I sanded them to size. It should be an easy and inexpensive rebuild.
Dan
Dan
Dan Sands
1969 365 GT 2+2 12629
1969 365 GT 2+2 12629