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Bush Mechanic

Identify Robert Bosch components.

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I'm attempting to resurrect a 1923 Metallurgique 12/15, which was totally disassembled about 60 years ago. I have been working my way through the big jigsaw puzzle for almost 2 years now, and feel that I'm making good headway. (There were two different worn out engines, each completely dismantled, and the parts mixed together in boxes. At least the boxes were stored out of the weather, unlike some of the car.).

 

I have two electrical components which were luckily left attached to the fire-wall, on the engine compartment side. Neither of them appear on the period Bosch wiring diagram, and I am at a loss as to their functions. I'm hoping that someone here is familiar with these, and can kindly solve the mystery. It is a 12 volt, negative earth system.

 

The first is about 80 mm diameter, and was located close above the starter motor. 

 

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Number 37 appears on the wiring diagram, on the starter, being the terminal leading to the magneto for the 'Power Boost' function when starting. I suspect that number 2 could be the extra power terminal on the ZF4 magneto, but it is not visible on the much-copied old diagram. The unit could possibly be an early ballast resistor in that line? Any ideas, Gentlemen?

 

The other item is around 46 mm diameter, and was fitted in the vicinity of the steering column.  

 

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It has three wire attachment points. My best guess is a horn relay, or something of that nature. (A horn was listed, but not shown on the wiring diagram). Does it look familiar to anyone, please?

 

The 'wiring diagram' is for the Bosch electrical system fitted to a number of European cars in the 1920's. Listed on it as users are:-  Austro-Daimler, Fiat, Benz, Diatto, OM, Opel, Mercedes, Metallurgique, Minerva, and Steyer. So any of these cars may well have the same components.

 

While this is predominantly a US car forum, it does cast a world-wide net, and hopefully some kind soul can enlighten me.

 

Thanks,  Mick.

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I don't know what the purpose is of the first item, I do know that the '2' refers to the cable that connects from the magneto to the magneto switch, according to the Bosch electrical coding. The '37' code isn't mentioned in my books which date from the 30's, so what ever it did, it was obsolete by then.

 

The second item is a junction box. Some Lancia Lambdas have a similar, or possibly the same thing mounted on the firewall. A Lambda owner would be able to tell you more.

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20 minutes ago, Craig Gillingham said:

I don't know what the purpose is of the first item, I do know that the '2' refers to the cable that connects from the magneto to the magneto switch, according to the Bosch electrical coding. The '37' code isn't mentioned in my books which date from the 30's, so what ever it did, it was obsolete by then.

 

The second item is a junction box. Some Lancia Lambdas have a similar, or possibly the same thing mounted on the firewall. A Lambda owner would be able to tell you more.

 

Thanks Craig.

I take it to mean that the '2' is the magneto off/earthing  wire. Is that correct? The magneto on the diagram shows two wires, the usual off, to earthing switch, and the 'power boost' wire from the starter. No doubt this one is only live when the solenoid is pulled in.

 

The starter is a three wire and earth model, with built in solenoid. Main power lead, energising wire, and #37 going to the magneto via a light (1.5 sq mm) wire. That is actually the lightest wire gauge in the diagram.

 

Lambdas are a bit thin on the ground here, but there is a Minerva or two about. I'll give them a try.

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Quote

I take it to mean that the '2' is the magneto off/earthing  wire. Is that correct?

Yes, that's correct.

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