Push button starter

[70spider]

So lets talk about the title of the post, Push button starter.
My confusion is the fact there seems to be 2 power feeds to the switch, the Black wire (30/1 terminal, source the alternator) and the Brown wire (30 terminal, source the starter motor). Why is this?
I have created my first draft on the push button system:

In the diagram I try to simulate the black and brown connecting in the "on" position as with the Fiat ignition switch.
My confusion is how do I deal with the brown wire? Is the diagram a good solution? Is the brown wire vital to the operation of the system or can I simply eliminate it? To me it seems redundant to have 2 12v inputs. Maybe I am to stupid to see the reason, it is just all my other classic cars (Ford) do not have a wire running from the starter to the ignition switch. Thier approach is a starter relay and the wire from the starter goes to the relay and then a wire goes from the relay to the ignition switch (simple).
I know most of you do not like this idea but it could be an inexpensive and reliable solution seeing how there seems to be no more Sipea switches left. All I need to do is figure out the wiring.
Thanks for reading.

[spider2081]

Maybe I am to stupid to see the reason, it is just all my other classic cars (Ford) do not have a wire running from the starter to the ignition switch.

for the ignition switch to function the battery + must go to the switch. Fiat used 2 battery+ connections on their ignition switches. Probably to reduce the load on a single set of contacts. The brown wire connection to the starter solenoid is simply connecting the battery + to the ignition switch so when the ignition switch is rotated to run or start it can power those circuits. The black wire on terminal 30/1 is the second battery + connected to an additional set of contacts in the ignition switch (15)
I believe terminals 30 and 30/1 are both battery + inputs to the switch. terminal 30 gets switched to Terminals "INT" and 50 . Terminal 30/1 gets switched to 15

I don't think your drawing illustrates how the original switch worked. I think it is showing both the black and the brown wire (+) connecting to the push button switch for the "start" operation. The original switches only used the brown wire to the "start"

[70spider]

I believe terminals 30 and 30/1 are both battery + inputs to the switch. terminal 30 gets switched to Terminals "INT" and 50 . Terminal 30/1 gets switched to 15

The original switches only used the brown wire to the "start"

Thank you for the clarification on which powers which that helps a lot.
So with that this is what I came up with:

It makes more sense.

[spider2081]

I don't see the reason for the 3 redundant switches to the right in your drawing unless you are just trying to use up the switches in the Jegs switch panel.
to replicate the stock Sipea ignition switch 2 toggle switches and one push button switch would accomplish what the Sipea switch does.

You wouldn't need the pink wire for key left in ignition switch warning as you are eliminating the ignition key.
The brown wire by itself would connect to one toggle switch the other side of that switch would connect to the "start" push button and to the Light blue/red and black wires.
The black connects to one side of a toggle switch. the other side connects to the pink and the light blue/black wires
Your drawing shows a switch being used to power a second switch? Why?

[70spider]

The black connects to one side of a toggle switch. the other side connects to the pink and the light blue/black wires
Your drawing shows a switch being used to power a second switch? Why?

I see your point on the redundancy of the extra switches. If I have the Black wire feed the switch and the pink and blue/black going out would tidy things up. Thanks for pointing that out.

[70spider]

Thanks for the information everyone. So I went back and looked on how I wired my fuel pump and O2 sensor and came up with a revised diagram, critique and offer suggestions if you see something.

As for the pink wire that piggybacks the brown on terminal 30 of the Fiat ignition switch, according to the diagrams it goes to the key in indicator light so I don't think I need it. Thoughts?

[spider2081]

I was hoping someone would replay with their thoughts.
I believe factory installed electric fuel pumps are installed with safety circuits so the pump will not operate with out the engine running.
Personally I don't know why one would add relays and fuses like your drawings shows to an existing working cars circuit. It complicates a simple circuit and adds more components and possible points of failures. I am assuming the fuses shown in your drawings are in addition to the Fiat installed fuses in the factory fuse panel.
For me dinghyguy's suggestion is the best option for your car. If the original ignition switch is in your car a logical repair for you is to attempt cleaning the switch contacts and reinstalling the switch.
Have you removed the ignition switch from the car and removed the electrical section? The issue could be more obvious than you think.

I have installed a number of relays in my 81 Spider. Their function and electrical locations remove the circuit load from the ignition switch, the steering column switch,and the coolant fan switch.

[70spider]

Personally I don't know why one would add relays and fuses like your drawings shows to an existing working cars circuit. It complicates a simple circuit and adds more components and possible points of failures.

Well it was just a thought. So I can just wire the 12v Brown and Black wires straight to the toggles in and run the others off the toggles out. I thought the relays would protect the system. I've used relays for the headlights, O2 sensor and the electric fuel pump (upgrade from the mechanical pump my spider didn't have an electric one).
Thanks for the help. As for repairing the old switch I don't feel comfortable, besides it would be difficult to trust it.
Besides this isn't a permeant solution I am just trying to get my spider running again until I can find a NOS switch that will work.

[spider2081]

As for repairing the old switch I don't feel comfortable, besides it would be difficult to trust it.As for repairing the old switch I don't feel comfortable, besides it would be difficult to trust it.

From your posts I don't see where you have removed the electrical section from your ignition switch to inspect it. The contacts are exposed once the electrical portion is removed from the mechanical portion. I like to put the key in the "off" position and remove the key from the switch. Then remove the spring wire that holds the electrical portion into the mechanical section. Remove the electrical portion by placing a small flat blade screwdriver under the plastic tabs and twisting it.
Once out a good visual inspection should make cleaning needs evident. Try not to rotate the switch mechanism
To reinstall the electrical section make sure the little drive dog in the switch housing aligns with the switches opening, then align the key in switch wires with the notch in the switch outer edge and push them together. Replace the wire spring retaining clip.
I like to test it holding it out of the steering column before installing it in the steering column.

[70spider]

From the pictures below you can see this switch is a bit different than the example one in the Mirafiori ignition switch repair post. I wonder if the reason is the car was bought by a service man in Hamburg Germany from the local Fiat dealer?




contact for terminal 50

contact for terminal 15
It is obvious the the contact on 50 is fried, so where to from here?

[spider2081]

I believe the switch you have photos of is the correct switch for a 1970 Spider. As I said in an earlier post there are at least 3 versions of the Sipea ignition switch. This is an early Spider ignition switch electrical section.
I would polish (file/clean) the contacts and test it out.
Keep in mind terminal 50 is the "start" contact. Your earlier posts stated terminal 15 was not working. How do its contacts look? I would clean all of the contacts before reassembling.

[70spider]

I took it apart a bit further.

the cam lobe that works the 15 terminal is significantly worn and doesn't allow a strong contact. This may have been the issue. I don't think there is a rebuild kit for these, is there?
Here is what the rest of it looks like.

This part looks ok with a little cleaning.

the contact points are worn down.

If there was a way to effectively build the cam lobe up so that it would engage the 15 terminal, that might be a solution.

[spider2081]

I would clean the portion with the arcs with brake clean ans a scotch bright pad. Clean all the points with a point file then bend the stationary contact so that the worn cam doesn't not have to move the movable contact as far for the contacts to mate.
My feeling is it took over 50 years of operation for the switch to wear like this. Meaning the switch design is pretty robust for the job it does. Cleaning and reassembling may not add another 50+ years but it might add 5-10 more years of reliable operation.

[dinghyguy]

I agree that the contacts can be salvaged. I wonder if someone with good computer skills and a 3d printer could make the nylon cam part? just a suggestion.

good luck
dinghyguy with the "other" type of ignition switch.

[70spider]

I agree that the contacts can be salvaged. I wonder if someone with good computer skills and a 3d printer could make the nylon cam part? just a suggestion.

That would be great, however I took a nylon fuel line nipple and formed it to fit the affected worn area and epoxied it in. It is a pretty good fit at the moment and when it cures I'll sand it down to match the original profile. I don't think there is a lot of pressure being applied to the cam so this might work. I'll polish it pretty good with 3000 grit sand paper and a light buff of acetone.
Thanks for your help.