Puch has no fuses

Further to Nick's pursuit of adding a battery to Puch lighting circuits, I notice that the Puch electrical circuits have no fuses. I' m surprised since the Puch is a very well engineered machine. I am guessing that if a short to ground occurred, the internal resistance of the armature coil is enough to limit the current for the wire size used and wire over heating would not occur. Does anyone know if this is the case or is there no built in current limiting protection?

Re: Puch has no fuses

I am pretty sure there is no limiting on the current, because i have found that once a light bulb, headlight, or taillight burns out, the other one will prematurely burn out. I have only seen one moped with fuses, and that was a Bainchi Snark. I could not tell if the were added on later by an owner, or if it came from the factory like that.


moped army

swarm and destroy

Re: Puch has no fuses

Hello, the Tomos has no fuses also... Doug

Re: Puch has no fuses

Ron Brown /


It appears that moped alternator outputs are matched to the load. Dan is right that after one bulb burns out, the other will soon follow because the decreased load results in a higher voltage to the remaining bulb. A fuse would not help this problem as this one bulb is not exceeding the normal current flow from the alternator.

On my Motobecane, the switches actually short the alternator output to ground when things are turned off. The turn on by removing the short to ground so I am sure the alternator coils are self limiting.

As an aside, it does seem that if you measured the headlamp and tail lamp current carefully, you could install a slow blow fuse on each circuit that would blow if the other bulb went out. Of course, blowing one fuse would cause the other fuse to blow so mayby carrying spare bulbs is the way to go. : )


Re: Puch has no fuses

As a sidenote to this conversation,my headlight went out day before yesterday 40 mi. into what would have been a 120 mi. trip.I was fooled into thinking it was a wiring problem as I'd just installed that 2-speed engine onto my Motomarina.You know how sometimes you're a little gun-shy when you make an engine swap? It would intermittently light and stay lit and then wouldn't come on for several switchings.Turned out that the filament of the bulb was just touching the electrode every once in a while.I had an extra bulb with me,but I chickened out and took off for home.Still an 80 mi. trip.Kinda' funny.That bulb is the same as a back-up light for an old GM car(#1156).So IT'S not hard to find.

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