Alternator junction box

Hi Guys:
Does anyone know what the correct alternator junction box looks like for a "M" series 246GT? I am pretty sure that all models earlier than the "E" series did not have fuses in the junction box. I have a broken block in my parts supply and attached is a photo of it...is this the correct block part of the box? If so, I guess I am missing a cover. If anyone can send me a photo of the correct block, cover, and attachment nut I would be very appreciative as I am trying to get the right parts on my car...I already have a reproduction junction box with fuses that go on a later E series car.
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Hi Guys:
Thanks a lot for the replies! This is good information that I have the correct block and I can at least reproduce the parts if I cannot find them for sale.

 

Hi Guys:
Thanks for all the info and photos! Peter, if you can provide the dimensions of the openings for the wires of your cover, I can use your photos to determine the rest of the dimensions to make a cover just like yours...it looks very authentic.

 

Hi Peter:
Thanks a lot for the sketch! With your sketch and photos (and my old block) I believe I can make an authentic looking junction box. I plan on modeling it in Solidworks CAD program and then sending the models (block, cover, thumbnut) to a 3D printer to have the parts made in nylon plastic. The thumbnut will have to have a theaded insert bonded into it with adhesive as a after-printing operation. Your thumbnut has the same detail design as the thumbnut on my car's thumbscrew on the electric windows fusebox...it is probably just a bit bigger as the nut is for a 5mm thread whereas the thumbscrew for the electric window fusebox is 4mm. Anyway, I will model all this in the next month or two and see how the printed parts come out...if satisfactory, I certainly will advise people (this post) where to get the parts made by 3D printing. I appreciate your willingness to share your solutions to problem parts and I would like to do the same to keep these cars alive and original. My car is s/n 01412 and a "M" Euro model which emigrated to USA. Just to beat this subject to death, my Scaglietti bodywork book lists the alternator junction block as Ferrari part number 591/400323...no indication of the original vendor though.

 

Hi Charles:
I dont want to get into the business of selling parts to others, but I will certainly direct people to my supplier (who is reputable) if I can get a good quality part made. Stay tuned.

 

Hi Guys:
I am in the process of having the plastic parts for the terminal box made right now using the 3D printing process...I will advise how this turns out when I get some parts. In the mean time, I have been thinking about this terminal box on the M series Dino...what is the purpose of the terminal box? It seems to me it has no purpose and actually can be a failure item. I do see that the later E series Dinos had a terminal box in the same location and it had 2 fuses for the the 2 wires coming off the alternator, so this later E series Dino alternator terminal box has a purpose. Maybe the 2 wires coming off the alternator to the terminal box on the M series car were originally fusible links. Does anyone have any knowledge about this? My mechanical parts book for my M series car shows the 2 wires are supplied with the alternator and do not have separate part numbers, so I suspect they may be fusible links. My electrical schematic diagram for M series car indicates that there are no fuses between the alternator and amp gauge and voltage regulator...so I am considering making these 2 wires between the alternator and terminal box to be fusible links if I can find the right wire. I want to retain the outwardly correct appearance of the car.

 

Hi Peter:
I see you have used the E-series junction box with the 60 amp and 8 amp fuses for your car. I have this box as well, and will use it if I cannot find any 60 amp and 8 amp fusible links to go with my L/M -series junction box...I will advise.

 

Hi Guys:
My plan for my M-series Dino is to use fusible links in the 2 wires between the alternator and alternator junction box. I measure the heavy gauge red color wire as 2.5mm or 10.5 AWG. I measure the small gauge white color wire as 0.9mm or 18-20 AWG. For the red wire, I will use a 14 AWG fusible link wire about 5 inches (13cm) long butt spliced into the 2.5mm wire. For the white wire, I will use a 22 AWG fusible link wire about 5 inches (13cm) long butt spliced into the 0.9mm wire.

 

Hi Guys:
My previous post about the measurements of my wires may be confusing concerning wire sizes. As a clarification, the red wire (heavy gauge) is 6.0mm*2 size per DIN ISO 6722. The white wire (small gauge) is 1.0mm*2 size per DIN ISO 6722. The AWG closest equivalent to the 6.0mm*2 size is 10AWG. The AWG closest equivalent to the 1.0mm*2 size is 18AWG. I plan on buying fusible links that correlate to the AWG sizes since I am not familiar with ISO or European standards for fusible links.

 

Hi Guys:
I have finally received the reproduction plastic parts to make the alternator junction box. These three parts were made by HV3DWorks (https://hv3dworks.com) using the 3-D printing process in nylon material. They made the parts to my specifications which were based on broken parts I have and images you guys have sent me in this thread. See attached photos. You can contact HV3DWorks directly to get the parts made. If you are missing all the parts for the assembly, you can buy the other metal parts on the internet as well:
1) 5mm threaded insert for thumbnut: McMaster-Carr part number 94510A402...press slotted end of insert into thumbnut.
2) Center screw, 5mm x 0.8 pitch x 30mm long: McMaster-Carr part number 93270A335...original Ferrari screw was 28mm long with a rounded end...so you can buy the 30mm screw and round the end yourself since I do not know who sells a 28mm screw.
3)Male side lugs: Kabel-Schmidt part number 733030...original Ferrari lugs were 2-piece assemblies...this part Kabel-Schmidt sells is a 1-piece design which should be better electrical conductivity.
4) Screw for side lugs, M3 x 0.5 pitch x 10mm long slotted cheese-head screw...many suppliers on internet....Belmetric.com for instance.
5) The rest of the nuts and washers for the above hardware can be found by many suppliers on internet.

The plastic parts are not as smooth and shiny as the original Ferrari parts, but they look authentic and are most likely more durable as the quality of nylon plastic they are made from is very good.

A final comment: if you go with this original style alternator junction box, I would highly recommend you add some fusible links between the alternator and the junction box. I am going to use a AWG 14 fusible link spliced into my 6.0mm*2 red wire and a 8 amp in-line torpedo-style fuse(I cannot find 22-24 AWG fusible links) spliced into the 1.0mm*2 white wire. Here are the parts I am going to use:
1) 14 AWG fusible link: Dorman part number 85622...this is not original Ferrari use but it is not visible as it is buried down inside the engine bay.
2) 8 amp in-line fuse: Mauser Electronics part number 576-276.5105.4802...this is not original Ferrari use, but it is not visible and it is a period correct design made by Littlefuse.


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