1957 Cadillac light switch on back doors

[Dennis Branch]

Does anyone know how to test the switch that controls the dome light coming on when you open the door on the rear of the car.
I grounded the unit and put a hot wire to it but it did nothing. Any help as always truly appreciated.
Dennis Branch
Ms Gulf Coast
57 Cadillac Sixty Series

[Roger Zimmermann]

If you connect the wire which is connected to this switch directly to the ground, the inside Illumination will come on if no other problem is present.
I believe the best way to check the switch is with an ohmmeter.

[Jon S]

I'm sure you know, it is a "reverse" switch e.g. makes continuity when in the open (released) position; off when closed.

[Dennis Branch]

Jon, I am not familiar with how it works at all. If you could explain to me and how it can be checked off the car I would be grateful!
Dennis Branch
57 Cadillac Sixty Series

[Walter Youshock]

Like a refrigerator door switch.  Door open, switch extends by spring pressure making contact.  Door closed, the plunger is retracted and the contact is off.  Only the rear doors should work those switches.  The front switches work the seat side lamps and dash map light, if I recall correctly.  The rear door switches should illuminate the dome lamps.

[Jon S]

To test it off the car, hook up a test light - negative battery to side of bulb, positive to switch connector and a third wire from side of switch to side of bulb.  You can use a flashlight 1.5V bulb and a D cell.  Bulb should light when plunger is out and go out when you depress the switch plunger.  Just like the refrigerator example Walter provided.  Good Luck!

[Dennis Branch]

You guys are the best, I am putting my  57 Cadillac Fleetwood back together one piece at a time.
Dennis Branch
Ms. Gulf Coast