Ignition switch help

[210bhp]

Sorry to post this as a link but perhaps you could help me with my ignition switch problem from my 67S which I posted over on DDK?

http://www.ddk-online.com/phpBB2/viewtopic.php?t=34898

Many thanks

Regards
Mike

[johntyboy]

Hi Mike

Hope you dont mind but to make it easyer I have just cut and paste the thread from DDK

I went to start the 67S and there was an immediate smell of burning from under the dash and no start. Immediately switched off and disconnected the battery. Thankfully nothing seems to have been singed, burnt or burst into flames. Took off the ignition switch and this is what I found.


One of the three spade connectors has come adrift from the bakelite base and obviously the wires still attached had touched some of the other connectors. I hope it has not blown anything in the circuits but will check that later.

So, to the question,
Does this three spade connector simply stick to the bakelite base with some kind of stickum or by other means? The central hole descends about 3mm into the bakelite and when I turn the key in the barrel I can see a small connecting ring appear at the bottom of the hole. How is this connected to the base of the spade plate at the top of the hole? Should there be a pin underneath the small ring (pictured) down the hole? I recovered the small ring from the footwell carpet but i cannot find anything else.
Otherwise I don't see how the circuit can be made complete from the bottom of the hole to the spade connector wires.

What am I missing here? A small pin or a lack of electrical knowledge?
Thanks for any help.
Regards
Mike

[210bhp]

Thanks John.
I have already worked out the piece I am looking for appears to have dropped inside the switch. I can hear it rattling about. So, can anyone tell me now how to separate the bakerlite top from the switch body?
There appears to be four crimped sections of the body which are 'flanged' over the notches in the edge of the bakerlite which would appear to need bending out. However, there is also a central pin which may be held on with a tiny circlip. Can anyone confirm if this needs to come off to get the two parts separated or does the bakerlite just slip over it?

Regards
Mike

[edmayo]

My memory is that the bakelite slips over the pin.

[210bhp]

Thanks Ed. Do you know if the two come apart without the internals escaping all over the place (making reassembly a nightmare) or will they just slot back together easy peasy once I have recovered the broken pin from inside?

Regards
Mike

[edmayo]

I think the only tricky part is that there will be a spring loaded ball which is what gives the detent feel as you go from one position to the next.

[Kilgore Trout]

I have taken these apart and have some pics I can post tonight. The case seems to be cast and the crimp holding it is punched, so you can't really bend the "crimps". I used a dremil grinder, carefully so the bakelite doesn't get damaged. Try not to grind the notches in the bakelite, you have to fasten the thing back together again.

The internals are simple, just keep track of the parts as it comes apart. The clip on the shaft will also need to come off. You will see what is worn out. In your case you will probably have to reattach your connection, a rivit perhaps? The piece that had worn on mine was the three point metal (what would you call it?) part that has the indents to make the contacts. Yours may have been scraping across the rivits holding the connector? Anyhow I cleaned up the part and turned it to make a better connection for starting. The indents seem to wear all the way through and turns into a sharp scraper to destroy the contacts. (and maybe your rivets)

I promise to post some pics tonight. These switches seem to be hard to find, at least through my limited efforts. I plan on a suitable backup switch for when it fails again.

Dan

[210bhp]

Dan
Thanks for your reply. In fact, I took the bull by the horns this morning and took the thing apart using my slit-lamp and various small tools at work today. I was quite happy how things went and I too will post pics later. I found three broken pieces inside the switch and if you post your pics I would like to work out how best to fix them back together. Many thanks again.

Regards
Mike

[Kilgore Trout]

First pics are one I just opened up tonight. Well, all that was holding it was the clip on the shaft, you can see that the notches on the bakelite are gone.

The three arm contact scrapes across the contacts on the bakelite. The example in my picture isn't that bad, it's not worn all the way through, only worn a little flat, I would use this one and rotate it so a good indent makes the starting contact, the one with the white ceramic, (I suppose) donut.

I am not sure how I would go about putting this one back together. The bakelite part has nothing to hold on to. The pics with the homade clips and the zip tie are of the one now in my car. That was my spur of the moment solution. I guess the clip on the shaft would hold it together some, but I would rather have it more secure.

[Kilgore Trout]

Here is the one in my car now with my clips...