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Discussion Starter · #1 ·
I hoping someone has better late night logic than i do. This toggle SPST switch in on my dash to activate the interior under the dash light and a dome light. It has a LED in the toggle that glows when the switch is on. An issue is, that like a lot of dome lights,I guess, the switch is on the negative lead (like a horn). I'd rather not re-wire the whole thing-especially since the dome light wires are under the headliner and I don't know exactly where under the dash they emerge.

As you'll note in the drawings, I can activate the lights, or the toggle, but not both which is what I want to do. Help is appreciated, as always.
 

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Get in, sit down, hang on
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Hmmm ... *scratches head*

How would this be wired in a "normal" (B+) circuit?
Would the center terminal be wired to ground provide a ground for the light?

If so ... would you wire the center terminal to B+ ???
(use a low amp fuse) LOL
 

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What is the pin out on the switch? Looks like if you hooked the light lead to the L/H pole and the Ground to the R/H pole the ind works......did you try hooking the center pole to the L/H pole and the R/H pole to ground?
 

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Discussion Starter · #4 ·
What is the pin out on the switch? Looks like if you hooked the light lead to the L/H pole and the Ground to the R/H pole the ind works......did you try hooking the center pole to the L/H pole and the R/H pole to ground?
Nope-woke up and thought of this about the same time you posted-telepathy? Sure hope not!
 

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life is a ride
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In your sketch #3 where the indicator LED works (lights) the switch must be in the open position. Voltage is present (through the filaments of the dome lights) on the dome light side of the switch only when the switch is open. When the switch is closed the voltage goes to 0 (ground) on the entire switch.
The LED will require a hot feed from the dome light circuit and the ground side connected to the dome light side of the switch with diode to block backfeed to the LED when the switch is open.
When the switch is closed (to ground) the LED and the dome lights should work.
Due to the design of the switch this may not be possible due permanent internal connections.
I would do a test mock-up of the circuit before installing it.
Post the internal connections of the switch for other possible answers.

vicrod
 

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Discussion Starter · #6 ·
Thanks,guys. In the end, I made the dome light hot all the time(it's got internal on/off switches) and re-made the under dash light to be a "normal" negative ground/hot through the switch feed so the toggles will work.
 
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