map light behavior and proper wiring?

[miketyler]

Well I must still have something wrong as I get no door activated maplight. It would appear as if I need to disconnect the existing ground to the switch and connect it to the door switched ground.

I am pretty sure I checked but will have to confirm that regardless of maplight switch position, neither switch poles ground to the switch case. Could this be causing this whacked out behavior?

[LAA66]

 I spent a day or so doing this same project. If I remember right the ground does go thru the door switches. Had a bad connection at the switch behind the kick panel. Also the toggle map light can be kinda finicky. 

[Robb]

my map light comes on with the doors.   the wiring in my car hasnt been compromised.


the way the door switches work, is that the circuit is open when doors are closed.  then when doors are opened the switches ground and the lights come on.

so that is the lights have 12 v going to them all the time, but when the doors open, then the cicuit is compeleted and the lights come on until the door is closed again (more specifically that the plungers are pressed in)

[miketyler]

My switch may be questionable. After looking at the diagram and reading all the info, it appears the switch should toggle between the door switched ground and its own body ground. I don't think its doing the latter. Wil have to check that again

[MEK-Dangerfield]

My switch may be questionable. After looking at the diagram and reading all the info, it appears the switch should toggle between the door switched ground and its own body ground. I don't think its doing the latter. Wil have to check that again

That was the problem with my map light. Power there, no ground. I ran a wire from the switch up to one of the screws holding in the glove box liner. You can't see my creativity since it all happens under the dash.   


  Mike

[VTMopar]

    MikeTyler -- thanks for starting this -- I have Exactly the same problem and can't wait to see if the suggestions here fix it (mine works when door opens, but not "independently" -- although it once did!).....

Vermont MOPAR

[Chryco Psycho]

i it is a simple cicuit , constnt power to the light , switch to ground at the light & ties into the yellow door switch ground circuit

[miketyler]

after more tinkering and fixing the RH door switch mine is working with the doors and the dimmer switch. However, like VM I have no maplight switch function. It does function to turn off the maplight if its already on from the door switch.

Yeah, its a simple circuit and I can't believe the time I have spent staring at the 72 schematic. The schematic doesnt show this but when the maplight switch is on, it provides body ground from the grounding strap to one of the terminals right? 

[Chryco Psycho]

yes

[miketyler]

well that may be my problem as neither terminal grounds to the switch case in either position. Is there an aftermarket source for a replacement? The ground to body requirement is probably not going be something I could get off of the shelf at Radio Shack.

[ShelbyDogg]

Mike, That switch at radio shack would be a commom SPDT (single pole double throw) switch.  The middle would go to the bulb, the the top terminal to ground and the bottom one to your door (yellow) circuit.

Rob

[71 DEPUTY]

3-switch in other position-- light is on- lamp is grounded via internal ground from switch to case.

factory manual doesn't show this " extra " ground by a symbol- to them it's a given known thing.

[LAA66]

  I sprayed some W-D40 on the base of the switch and things improved. I believe a Two pole bulb is used in the dome lamp also. The power needs to go thru this light to complete that circuit.

[miketyler]

I hooked up my switch to a VOM and the grounded terminal is not grounding to the case. The angled terminal is the one that supplys case ground to the circuit. It has an additional tab that extends to the edge of the phenolic cover plate and is sandwiched between the cover plate the the edge of the metal switch housing. Very simple fix is to solder a jumper on the case to the base of the terminal to restore case ground.   

My problem is not only that the switch isnt grounding but that my yellow wire is hot when the doors are opened and extinguishes when they are closed. I had an SPDT to test with and it restores both functions to the light as it is. rather than trying to figure out where my yellow door ground is getting power from. Thanks for that advice!
   
My bulb is a single filament type and the socket is for a single filament bulb as well; maybe yours has been swapped along the way.