Lucas 3 position headlight toggle switch

[picah]

I am close to finishing the dash and main harness wiring and have a question. I am using the standard 3 position Lucas toggle switch for the headlights (off-dimmers-headlights) with floor mounted dip switch (high/low beams). I'm using two Bosch relays for the headlights.
Question: should the power into the switch come from the ignition switch (12V switched power) or from the starter solenoid post (hot all the time HATT)? Is the only difference the ability to have my lights on with the ignition off or is there a better choice from a safety perspective. Remember, I am using relays so there is very little power (amperage) going through the toggle switch.
Thanks for your input here. The wiring doesn't have me freaked out, but I have been needing to ask various questions to help me achieve good functionality as well as good measure of safety.
Best
Ron

[Gaz64]

It should be battery fed, that way any light function can be operated without the ignition on.

Would you want the lights going off at night, if you shut the engine down for some reason?

Gary

[LMH]

The parking lights would need to be able to be on w/o the engine or ignition switch being on.
Larry

[patrickt]

Originally Posted by picah

Question: should the power into the switch come from the ignition switch (12V switched power) or from the starter solenoid post (hot all the time HATT)? Is the only difference the ability to have my lights on with the ignition off or is there a better choice from a safety perspective.

The traditional feed to the Lucas switch is from the "always hot" post on the ignition switch -- and a zillion cars used this same wiring pattern in the 50's, 60's, and 70's. The danger in this set up is that the Lucas re-pop switches can only handle 15 amps, maybe, if you're lucky, and you will also experience significant voltage drop through the crappy Lucas re-pops. Go here for a discussion and easy upgrade, both for performance and safety: Headlight Wiring Upgrade