55 Thunderbird door jam switches

J

jeffstuarts

Junior Member
Hello All,
This is my first post on this forum. I am helping a friend with his 1955 Thunderbird and have very little knowledge of these cars. The question is on the door jam switches. They have 12 volts going to them and we assume that these operate dome or interior lighting but cannot find any. Also, they have no continuity through them when released or closed. Any help in this is greatly appreciated!
Jeff
 
Do you mean you can't find a dome or interior light fixture (bulbs)? My 54 had very dirty switches. I sprayed them a lot with carb cleaner/brake cleaner, kept pushing min and letting pop out, and now they work. My 54 customline has a fuse for the dome located on the engine side of the firewall.
 
No "dome light" because the roof is removable.
The door switches operate a map / courtesy light above the radio. (photo 1, yellow arrow)

With voltage at the door switches the fuse is good. It's a small glass fuse on the front end of the headlight switch. (photo 3)

There is also a manual switch on the face of the map / courtesy light.
If the bulb is burned out Do Not try to replace it by taking out the plastic lens, if it still has one.
They are very fragile after 70 yrs and will disintegrate. It's also apparently a discontinued part, no longer available.
The original size bulb will not fit thru the face of the light fixture anyway.

The bulb is in a spring tension socket that pops out toward the inside of the dash.
(photo 4, radio removed)

'55 T-Birds were originally 6 volt Positive ground. Depending on the workmanship of the 12v conversion on your friends '55 you'll very likely come across things that will have you scratching your head. More info at this link...
https://www.ctci.org/battery-for-6v-to-12v-conversion/

Oldgearz suggestion to use a contact cleaner in the door switches is likely a good one. If that fails new replacement switches are available.
 

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Thank you for your responses! The next step will to check the circuit of the light above the radio. First, of course, is to see if there is even a working bulb there. Then we'll see if jumping across the switch activates the light.
Again, we appreciate your help.
Jeff
 
The map light lights when turned on manually so the power to the lamp and the bulb in it are good. However, even when we jump across the door jam switches, it does not light. There is 12v power to the switches. Based on the schematic DMSFFR provided, I'm guessing that the wire from the switches to the light is broken somewhere. We will try to get under the dash and see if we can see anything.
Jeff
 
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