Hi/Lo beam/horn button?

[Jordan]

How about just putting in an inline fuse holder?

How would that help?

From my experience with a Moto Guzzi Ambassador, I know that the old CEV switches can fail due to corrosion and moisture on the contacts. After my first switch failed on the Guzzi I would take off the cover and spray the switch down with WD40 any time I rode in the rain. It survived for a lot of years with that kind of maintenance.

Your 12 volt Guzzi is in a better position to start with.
I think the main problem is the plastic, which goes soft when subjected to heat, caused by high current flow. When it starts to deform it all goes wrong.
Reducing current flow to the small amount that a relay needs fixes that.

[DewCatTea-Bob]

[quote= Moto Chuck ...
" How about just putting in an inline fuse holder? "

____ You mean with a fuse that's rated for JUST the minimum amount of amperage required only for just the headlight-circuit*itself ? - (* Instead of only relying on just the stock [over rated] fuse that's supposed to protect the entire lighting-circuit.)
Cuz otherwise, such a proposed remedy would-not provide any significant additional protection for saving the Hi/Low-switch from built-up overheat-damage. _ And besides that,, when a switch-connection has progressed into a heated-connection, it then passes less current, which of-course lessens the strain on the fuse (thus pretty-much assuring that it would provide NO effect) !
__ But lets say the added-fuse was always sure to do it's intended job of saving the switch from ever overheating,, the fuse's current-limit would have-to be of such a low amperage-rating, that it would then be blowing-open on a frustratingly regular basis.
And-also, installation of a relay is really no more difficult than installing a pair of in-line fuses.



" I know that the old CEV switches can fail due to corrosion and moisture on the contacts. "

____ Right ! ... As contrary to pop.belief, it's not the normal current-flow that overheats a (capably suited) switch,, but rather a poor contact-connection that can't pass the amount of current which the circuit demands. _ And-so whenever such a secondary bottle-neck forms at the switch-contacts, that poor-connection then becomes as a 'load' (since it is no-longer preferably acting as a 0-ohm conductor), and therefore must handle wattage which it's unable to adequately disburse without creating an amount of heat that the plastic-parts can't cope with !



" I would take off the cover and spray the switch down with WD40
It survived for a lot of years with that kind of maintenance. "

____ I'm thinking that you would've spent less time & trouble if you had rather installed a 'relay'.


Dukaddy-DUKEs,
-Bob

[Moto Chuck]

Yea, I guess that a relay makes as much or more sense since it is the high current load that can add to the high resistance contact that creates heat. I still think that the single cylinder ducatis are not very well protected electrically.

[DewCatTea-Bob]

[quote= Moto Chuck ...
" I still think that the single cylinder ducatis are not very well protected electrically. "

____ You are certainly right about that ! ...
The three stock fuses should each have their original amp.rating-values reduced down-to just 8 to 12 amps (for 6-volt),, and, a master-fuse of 20 to 30-amperes should be installed on the battery's ground-lead to the frame !


Dukaddy-DUKEs,
-Bob

[Jordan]

Yea, I guess that a relay makes as much or more sense since it is the high current load that can add to the high resistance contact that creates heat. I still think that the single cylinder ducatis are not very well protected electrically.

Even with a new switch and nice clean contacts, a high current going through this puny switch creates heat. The switches just weren't made to last long, as installed.
OK in the days when they were cheap and plentiful.

[m82a1]

Not to hijack the thread and somewhat on topic. Are the Matchbox relays still available? I have used these with great success on two bikes.

Ken

[DewCatTea-Bob]

[quote= m82a1 ...
" Not to hijack the thread "

____ Not a big concern,, as so long as any new post-topic doesn't jump-aside off-ward onto some flimsy tangent extension off-from a relevant-tangent of the original thread-topic, then it's really not to be considered as any 'hijacking' of the established thread.
So your inquiry really doesn't require any excuse at all !



" Are the Matchbox relays still available? "

____ Well I certainly wouldn't be surprised if they weren't being produced any longer ! _ Cuz while they were a nicely made packaged-unit,, at up to near 50-bucks each, they were way,way over-priced !
As these-days,, ya can get* smaller relay-units which are also stronger, for under 20% of that price. _ (* At shops like Radio Shack.)
____ I only know-of fellow-member Bruce to make extra good-use of relay-units on a Duke, so maybe he'll chime-in with mention of whatever brand/model of relay-units which have worked-out best for him.


Duke-Cheers,
-Bob