Mach 1 Brakelight Switch

[Octane]

So I'm having some issues with the brake light switch on my bike.

It appears to be a NOS Apprilia switch.

With the brake pedal up, and the the switch all the way it, it makes a circuit and switches the light on.
When the brake pedal pressed, it pulls the switch and the circuit is broken, and the brake light goes off.

So it appears I have a 'normally on' switch instead of a 'normally off' switch. Does this sound right? Can the switch be swapped so that its normally off, or do I need to get a different switch?

[Octane]

Ok, new devellopment.

This is the style switch.


I pulled the switch apart, and managed to bend the little brass contacts 180degrees, so they point up instead of down. This means the circuit was broken when the switch is in its natural state, and the circuit is made when the plunger is pulled out.

Tested with a multi and it appears to be working, so will mount it back on the bike tomorrow and see how I go with it

Curious to hear other peoples thoughts on this though as I cant imagine that this is the correct thing to do.

[Jon Pegler]

The later widecase machines use a switch like yours.
These are off when the plunger is depressed and make a contact when it is fully out.
You could wire it up through a relay to get the required set up.
It's probably easier to get a switch with the opposite opening/closing positions for a Mach 1.

Jon

[DewCatTea-Bob]

By: Octane...
" With the brake pedal up, and the the switch all the way it, it makes a circuit and switches the light on.
When the brake pedal pressed, it pulls the switch and the circuit is broken, and the brake light goes off. "
So it appears I have a 'normally on' switch instead of a 'normally off' switch. Does this sound right? "

____ Not really...
A 250 Mach-I uses it's battery to power the brake-light, and the related n-c.type b-l.switch is normally-open (& held that way by an internal-spring),, and when the foot-lever is pressed-down, an external connecting-spring (between lever & switch-plunger) then overpowers the internal-spring & pulls the switch-plunger outward to make internal contacts close the intended circuit.
This is the type of switch your particular n-c.model should have, rather than the w-c.type you've pictured, (however there are three types in all).
__ Your-own explanation seems to be describing the action of the type of brake-switch intended for the batteryLESS Mark-III & Motocross 250-models.
This type is designed/built to function the same-way PHYSICALLY (as the battery-type) but, except instead, it's rather made to be normally-CLOSED, so that when the brake-lever is pressed-down, the internal-contacts' connection is then broken-open (and the normally-intended current-circuit to ground leaves the AC-flow no choice but to then flow through the brakelight-filament [which is otherwise kept shorted-out] ).
__ The third & newest b-l.switch type is only intended for wide-case models, and works with a different physical arrangement. _ IT may seem confusing to those who already have a well-established understanding of the older types, cuz the w-c.type switch itself is NORMALLY-closed, however, installed on a parked-Duke, it's then kept OPEN (normally), by the foot-lever...
This quite notable difference is due to two alternate factors,, first, the internal-spring performs both of the jobs intended by the two separate springs of the older/n-c setup, and second, instead of having the foot-lever pull the switch-plunger outward from the switch-body (when lever is depressed), it rather PUSHes the plunger into the switch-body (when lever is not depressed) ! _ This is the case because it's internal-spring pushes the plunger outward, instead of trying to keep it pulled-inward (like the n-c.type do).
So when the w-c foot-lever is lowered, the internal push-spring can then force the internal-contacts to complete the circuit-connection, (instead of having an external-spring pulling [the plunger] by the depressed n-c.type foot-lever).
And when the w-c foot-lever is in it's normal/undepressed-position, the foot-lever return-spring then presses the lever against the switch-plunger, (pushing it inward against the weaker internal push-spring), to then force the internal-connection to break-open the circuit.
Of course this is all quite fairly simple for those who don't also have the older/n-c type setup kept in mind to possibly get the various details confused with.


Dukaddy-DUKEs,
-Bob

[Octane]

Thanks guys.
Basically, I just bent the internal contacts 180degrees, so the plunger does not make contact with them in the brake off position, and does make contact with them in the brake on position, thus closing the circuit and switching the light on. Silly me forgot to take photo's while I was doing it though, so I cant show you guys what I mean. Hopefully you understand though.
Anyways, I've just installed it on the bike and its working fine now.

Only need to tune the carb and then it's ready for registration in a couple of weeks

[DewCatTea-Bob]

" This is the style switch. "

____ That which you've pictured, APPEARS to be a w-c.type, but may be intended for some other Italian-bike, as those switches weren't made by Ducati and so may have other characteristics.


" I pulled the switch apart, and managed to bend the little brass contacts 180degrees, so they point up instead of down. This means the circuit was broken when the switch is in its natural state, and the circuit is made when the plunger is pulled out. "

____ Either the circumstances or your wording doesn't properly add-up...
The type of switch you show itself has a "natural state" of being with it's plunger (kept internally pushed) fully-extended outward, and thus can't be "pulled out" further !
Seems as if you've taken a normal-working w-c.type switch and altered it to keep it's brake-light lit at all times except when the rear-brake lever-pedal is depressed. _ Just opposite of legal-requirements (for when mounted on a stock w-c.setup) !
And as you've reversed-altered it, when installed on a narrow-case model (with stock-setup), then the brake-light couldn't ever be turned-on, (as the plunger would always be kept in it's [new] off-position) !


" Tested with a multi and it appears to be working, so will mount it back on the bike tomorrow and see how I go with it "

____ It may now ELECTRICALLY function backwards (as you thought you wanted), on some "bike" or another, but, in a narrow-case type 'DUKE'-application (such as a "Mach I"), it can't PHYSICALLY function properly, (even with a n-c external-spring trying to pull-out the plunger) !


" Curious to hear other peoples thoughts on this though as I cant imagine that this is the correct thing to do. "

____ I've never heard of any need to do what you've done (to a stock Ducati brake-switch) !
__ Those switches are known to have limited lifespans, as their body-parts get loosened die to vibration.
By tearing-into it and sticking it back together, you've likely either shortened or extended it's life-expectancy.


Hopeful-Cheers,
-Bob

[Octane]

The image was just one I found by doing a google search. The one on my bike may be different as you cant see the internals of the switch shown above.

The switch on my bike is a NOS Aprilia switch that is spring loaded so the plunger stays in, and in contact with the internal contacts. Thus allowing 6V to pass through and power the stop light.
When I pushed the brake pedal, this would pull the plunger out, and off the internal contacts, breaking the circuit and causing the light to go off. Exactly the opposite of what I need.

So, as mentioned, I reset the internal contact plates so that the plunger was NOT in contact with them when the brake pedal was up, then when the brake pedal is pushed, the plunger is pulled OUT and makes contact with the internal contacts and thus switching the brake light on.

Here's a very rough MSPaint drawing of the switch in its natural state. I bent the internal contacts from the black position, to the red position.


Anyways, its all re-assembled and working as it should now. Pedal pushed, brake light comes on.

[DewCatTea-Bob]

" Basically, I just bent the internal contacts 180degrees, so the plunger does not make contact with them in the brake off position, and does make contact with them in the brake on position, thus closing the circuit and switching the light on. "

____ Well this statement seems sensibly logical IF you were mounting that switch on a stock w-c.model and it wasn't made for a 'Ducati' ! _ Otherwise, your presented story on all this doesn't add-up (and is disconcertingly-confusing to top Duke-experts such as myself) !


" Anyways, I've just installed it on the bike and its working fine now. "

____ Seems unbelievable ! - What kind of a "bike" is it. ??
Just what do you really have that switch mounted-on anyway ? _ Did perhaps someone sell you something that was quite other than a "Mach I" ?
How about posting a picture of your Duke, and especially a pic or two of the area where your pictured brake-switch is actually mounted-up !? _ Cuz that would then be all-telling for all those of us who correctly understand the facts (as I've presented them concerning the 3 switch-types), and have found your whole-story on this switch topic to be disconcertingly (miss)correlated.


Hopeful-Cheers,
-Bob

[DewCatTea-Bob]

" The image was just one I found by doing a google search. "

____ Alright, NOW we all can finally realize what the misleading problem was with your brake-switch story ! ...
The picture you posted (of a w-c brake-switch) was not an ACTUAL picture of your very-own particular switch !


" The switch on my bike is a NOS Aprilia switch that is spring loaded so the plunger stays in, "

____ That's consistent with both n-c.type brake-switches !


" When I pushed the brake pedal, this would pull the plunger out, and off the internal contacts, breaking the circuit and causing the light to go off. Exactly the opposite of what I need. "

____ Right, your battery-powered n-c.model needs the internal-connection to become closed-circuited in order to power-on the brake-light !
__ Where did you get your nos.switch from ? _ You had acquired for yourself a more rare switch-type which was intended for the Mark-III & pre-1966 SCR 250-models, which use AC-power (direct from the alternator) to power the lighting.


" I reset the internal contact plates so that the plunger was NOT in contact with them when the brake pedal was up, then when the brake pedal is pushed, the plunger is pulled OUT and makes contact with the internal contacts and thus switching the brake light on. "

____ That all makes completely logical-sense now !
You seem to have converted your AC.system-type brake-switch into the (more common) battery-system type of switch.

____ BTW, is YOUR switch's body black or gray in color ?


Content-Cheers,
-Bob

[Octane]

Bob,
I'm sorry if the way I've presented this problem has confused you, but please don't start to question the authenticity of my bike, or my common sense. I may not be an expert on vintage Ducati's like you, but my family has 2 restored Mach 1's, a 160 Monza Jr, and a 750GT on top another 7 or 8 Duc's that have since gone to other owners, and I'm a fitter & turner by trade, so I have a fairly good understanding of how things are supposed to work.

I did check the brake switch on the other Mach 1 and that one was working as it should, which is why I posted this thread up asking for thoughts on my brake switch as it was working the opposite way. IE Switching the light on when the brake was off, and switching the light off when the brake was on.
The simple and most likely explanation is that the previous owner installed the wrong switch as Jon suggested.
The simple solution was to reverse the way the switch works as I've done in the drawing above.

Tested and working fine.