light switch power source?

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06boblee
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light switch power source?

Post by 06boblee »

Is the light switch powered direct from battery or ignition?
'54 M37 wew
MVPA #16921
Cal_Gary
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Re: light switch power source?

Post by Cal_Gary »

I'm not an expert since I run the Painless Performance harness; however, I believe ignition as I don't recall any secondary wires running out of the battery box.
I know that headlight switch harness is complex as the switch has the options to power off all your lights, go to service drive, or switch to BO mode.
Gary
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1954 M37 W/W
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John Mc
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Re: light switch power source?

Post by John Mc »

The light switch normally works whether the ignition is on or not.

Per the wiring diagram:
Wire 82 is the battery cable running from the battery to the starter,
From that same terminal on the starter, wire 4 runs to the voltage regulator.
Wire 10 runs from the voltage regulator to the circuit breaker
Wire 11 feeds all the circuit breakers and he ignition switch
Wire 15 leads from one of the circuit breakers to feed power to the light switch

So all of the circuit breakers, including the lights, get their feed from the same place as the ignition switch. Unlike most modern vehicles, their power is not dependent in any way on the position of the ignition switch.

I can dig up a wiring diagram, if that would be helpful. M37B1 is a little different than the M37, but the part described above is he same.
Last edited by John Mc on Thu Aug 26, 2021 7:01 pm, edited 1 time in total.
1951 M37 "Brutus" w/Winch and 251 engine
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vit16
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Re: light switch power source?

Post by vit16 »

Correct, they are in parallel.
06boblee
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Re: light switch power source?

Post by 06boblee »

Thanks, you all have been a big help.
'54 M37 wew
MVPA #16921
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