Map light only works with doors open???

Got me a map light switch thats post to be a good one for my 72 dart, put it wear its post to go under the dash, but with the door closed it don't work flippin it up or down, but with the door open the light comes on with it fliped down.

My volts on plug of map switch.
Brown wire with door open: 12.15v
Brown wire with door closed: 12.43v
Yellow wire with door open: 0.165v
Yellow wire with door closed: 12.53v

I did haft to cut a switch plug out of a 71 Dart parts car to put in mine, because someone has cut mine out & yes I put Brown on Brown & Yellow on Yellow.

What do you guys think, why it ant working with doors closed???

Not sure about the 72 dart but the barracuda needs a switch ground strap to make the map light work properly... The door pin switch simply grounds the light to make it work with the doors open...The actual map light switch will send the ground to either the door pin switch or to the dash frame ground which turns the light on at any time, doors open or closed...

as said either the socket side case of the bulb (if a single contact base) or one of the base contacts (if a dual contact base) bulb needs to be grounded at all times then you have simply power to the switch/thru it to the bulb. Not sure how the map light is connected to the dome light tho so I might be missing something

Since the dome light system and map light turns on via door Jam Switch, map light BULB must be isolated from Chassis ground.

Positive source to bulb in both ( dome and map ) is constant from batt

The Map light switch should provide the ground when dome light is turned off.

How it works ? switch must have two positions... one what closes the circuit with Dome light system alowing to turn on when Dome light lights up ( via dimmer wheeel or door switch ), and the other one what cuts this circuit and closes the circuit with chassis ground FEEDING the switch, not the bulb socket.

being this the truth, the map light bulb should be two contacts one filament just exactly like the 1004 dome light bulb

this is how should work the Map light

( forgott to add on diagram, the yellow wire signal is of course negative )

Yell thats only thing I could think of is switch not grounded good or switch may be bad.

to support the ground strap deal... here is what I found on an ebay auction



that would make the switch having just two prongs instead three

however, this is also from an E body

switch is grounded. I hooked a clamp jumper wire to a know good ground on the dash, run to the nut on the switch & I put the jumper wire & other places too, steel only works with door open.