Dome/Map Light Circuit. Can anyone explain how it works? Diagram?

Any single ground will complete circuit. If you have 12 volts at door jamb switch you are measuring before the open, light bulb is carrying the voltage bit with no flow (open door jamb and headlight rheostat)it does not illuminate.
 
What is probably complicating this is the car probably has the headlight warning buzzer. The door switches are probably not grounded.

The power for the dome light still comes from the fuse block (Dome/Brake) (pink wire) from there it goes to the brake pedal switch (just a splice, no switch functions). At that point it goes to the connector at the kick panel. From there the pink wire goes directly to the dome light.

Now the yellow wire is a different story.
Here we will follow the current to ground (away from the light).
From the dome light the yellow wire goes back to the same kick panel connector.
On the other side of that connector there looks to be two wires, one goes to the left door (looks to be a 1 wire switch) and the other continues.
From the kick panel connector the yellow wire continues to the dash dimmer/dome switch (again just a splice).
From that splice the yellow wire continues to the right door switch (looks to be a 1 wire switch).
That is probably without the warning buzzer.

The two wire door switches probably isolate the ground, I'm guessing in the warning buzzer/relay.
The buzzer takes the dome light grounds so if you open the door the buzzer goes off.
There is also a feed from the headlight switch (park lights) that goes to the buzzer as a power feed, not sure why it would need its own power as the park light feed should be able to power the buzzer.

Bottom line you can't check power at the door switch as it is just a ground, single wire or two.


Either way it is relatively a simple circuit.


So back to the original question, we would need to know is you have the buzzer or not (one wire or two on the door switches)


Alan
 
I just realized this is one post not two different ones, old issue (2014) alarm wiring, we'll forget about that.

New issue, stuck on dome light.

Still need to know is you have the buzzer or not (one wire or two on the door switches).


Power (+) at the fuse (pink wires)
Ground (-) at each door switch, dome/dimmer switch, and the buzzer, odds are one of those has failed.


Alan
 
This circuit does not appear to use a conventional ground. It appears to be a circuit that sometimes grounds and sometimes feeds power to the circuit. It really has me stumped.

Part of my problem debugging it is the fact that I have a generic “1968 Chrysler” wiring diagram. It appears to be the same as my Newport but wire colours are not the same and I don’t know if it is actually the same. I am not able to find the specific wiring diagram so some of this is guess work.

Spend $30 on this:

1968 Chrysler Color Wiring Diagram

Between it and the FSM, you will eliminate most of the grey area.

The map light switch could be dirty/worn/compromised. Try jiggling the switch a bunch of different ways during actuation to see if it has any effect.

My approach to diagnosing:

When it comes to the electrical system, don't guess.

Learn what is right and fix what is wrong.

Guessing can turn your car into a charred pile of scrap metal.

Hope the input helps.

John
 
So back to the original question, we would need to know is you have the buzzer or not (one wire or two on the door switches)


Alan

FWIW, none of my '67 Newps have an ignition buzzer, nor does a buzzer circuit show up in any diagrams..

My speculation is buzzers showed up in '69 or '70 when the ignition switch moved to the column?

John
 
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