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I am contemplating having all of my electrical lights and cigar lighter, (other than the starter switch circuit), controlled by the ignition switch. Below is a pic of a standard install.


Ammeter, relay and ignition switch are wired with 10AWG.
Generator outputs 20 amps.
Ammeter feeds the ignition switch which feeds the relay and fuse panel.

I have the keyed ignition installed just before the circuit breaker relay. The circuit breaker relay then feeds a 4 circuit fuse panel. (1-cowl & coach lights, 2-cigar lighter, 3-all other lights, 4-temp gauge)

Looking for positive and negative comments...

Thanks for your thoughts.

Gar

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Do you have a schematic of that you're planning?

I have just a couple notes:
- With only a 20 amp generator you should be able to use 12awg wire instead of 10. But really the only reason to do so is that it's easier to work with. It's cheaper too but that's negligible compared to the value of the car.
- Traditionally cigar lighters are not switched by the ignition so if I were you I would have yours that way. And by "traditionally" I mean up to the mid-2010's.
- Is your horn electric?
- What are the values for the fuses? And is all the current going thru the ignition switch, or does the switch power a relay for the accessories?

-Yes the horn electric.

I use 10 AMP fuses for the #14 and #16 wires and 15 AMP fuses for #12

ALL power goes from the:
ammeter --> IGN switch --> relay -->fuse panel or
ammeter --> IGN switch --> relay -->coil

Horns and lighters are heavy current draws. Usually they are unfused and not run thru the ign switch. Those diagrams I looked at have the horn relay fed directly from a constant hot wire. Some models did run thru the ammeter, others not.

Didn't find a spec for your model but the mid 30s and onward years that did provide specs list on average 22-25 amps with two horns and 33-36 with three. With that logic a single horn is drawing around 12 or so amps so if you are going to fuse or switch it on or off I would plan accordingly. Lighter elements have a fairly low resistance when they connect up and probably draw that much if not more.

Howard:

Thanks for the input.

I will move the cigar lighter off the ignition switch and feed it off of the ammeter with an inline fuse. (I just picked up a couple from YNZ)

I appreciate everyone's input.

Gar

Only issue is can the switch contacts handle all the amperage?
If no, then you need an amp rated relay in the circuit.
I doubt the ignition switch is rated for that much power or they might have done this from the factory.
A cigar lighter will pull about 20A itself. It may work but at some point may melt down.
The battery is the amperage culprit, not the generator output. Anything connected gets full power.

Unless you have a 50 amp ammeter I would not even run a cigar lighter off of that. I believe on a 6V system they use 15-20A.

Common practice was that both the horns and cigar lighters bypass the ignition switch and are fed from the ammeter.

Yes but AFAIK ammeters are only rated for the current they can display. I would be cautious about hooking up high current loads to it if it's, say, a 20 amp ammeter to match the 20 amp generator.

Not only that but putting the horn through the ignition whether by relay or not my violate vehicle code so be sure to check it first.