72 dome, map light questions

[swifty]

I have a 72 swinger with the map light option. My question is how is it supposed to work? Now it is on with the dome light when either door is open or headlight switch turned left. Flip the switch and it is off all the time. I thought I read somewhere it is supposed to be on with map switch on.

 

[95teetee]

in my Scamp, the only thing the map light switch did was turn the useless little light under the dash on the passenger side. Not sure if that was what it was supposed to do or not...

 

[1969383S]

Switch one way it operates with doors and headlight dimmer switch. The other way just turns it on regardless of doors or headlight dimmer.

 

[RedFish]

It should add to the interior lighting when a folded paper map is spread in the passengers foot well.

 

[swifty]

Does anyone have a better accessory wiring schematic other than the factory 72 plymouth one I downloaded from here. The factory one leaves alot to be desired. I look at schematics all day at work and struggle with this one. How does the map switch feed the lamp.

 

[67Dart273]

You downloaded the 72 shop manual here?

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

I know of nothing better. I will admit, poorly documented

 

[swifty]

You downloaded the 72 shop manual here?

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

I know of nothing better. I will admit, poorly documented

Yes this is the one I have. I have trouble following where wires go and what switches do, wish it had no, nc contacts and more info for relay contacts.

By looking at the schematic on 8-148, does the map switch just ground the circuit? So if I ground the brown wire at the switch, just the map light should light.

 

[67Dart273]

BE CAREFUL

The "traditional" yellows were the switched ground circuit of the dome lamps, but in that diagram, the seat belt and IGN sw lamps yellows are "hot."

I'm not sure I ever figured that all out, partially because the map switch nor the special door switch used on one side are diagrammed. You might want to "ohm" those two out

I've suspected that the map switch is switched to ground, IE the switch itself must be mounted and grounded

 

[swifty]

I can't figure it out either. I will have to check it out on the car which is 60 miles away right now. Just trying to get a plan together. If I ever hit the lottery i will hire a bunch of electrical engineers to draw up some better schematics and post them for everyone.

 

[RedFish]

I think you already have it wired right. The switch operates that lamp providing secondary light. If the dome lamp primary isn't on isn't on the secondary cant come on. The switch allows primary without secondary. I hope that makes sense.
You could toss the wiring diagrams and run tour own wiring to the map light and switch thus creating a battery killer.
Or you could add foot well lighting, 1 or more, all on the primary circuit, no switch required.
Does it matter that those large origami folded paper maps are no longer produced ? LOL

 

[D Cluley]

Assuming that '72 is the same as '74, then yes the switch is in the ground side of the circuit.

With the switch in one position the map light is connected directly to ground through the dash frame and turns on.

With the switch in the other position the map light is connected to the yellow wires of the dome light circuit, so the map light comes on when the doors are open or the headlight switch is turned.

On my '74 the hot wire for the map light is pink, the same as the hot wires for the dome light, trunk light and the glove box light (the other lights with ground switches) and the ground wire from the map light to the switch is brown, and the wire from the map light switch to the dome light circuit is yellow (the same as all the dome light ground wires.)

 

[swifty]

Assuming that '72 is the same as '74, then yes the switch is in the ground side of the circuit.

With the switch in one position the map light is connected directly to ground through the dash frame and turns on.

With the switch in the other position the map light is connected to the yellow wires of the dome light circuit, so the map light comes on when the doors are open or the headlight switch is turned.

On my '74 the hot wire for the map light is pink, the same as the hot wires for the dome light, trunk light and the glove box light (the other lights with ground switches) and the ground wire from the map light to the switch is brown, and the wire from the map light switch to the dome light circuit is yellow (the same as all the dome light ground wires.)

Thanks I will check if mine is the same, sounds like it is. I might have a bad ground to the switch.

 

[moparker]

Why is this such a pain in the ***. Do I need to pull the radio out to see where to connect the wires?

 

[1969383S]

The 2 contacts on the switch have continuity to each other when the switch is in the normal posistion. This allows the ground signal from the door switch to pass to one side if the lamp.

When the switch is moved to the opposite posistion it grounds the lamp terminal to the case of the switch completing the circuit to ground. If the switch does not have a good connection to ground it will not work.

 

[swifty]

The 2 contacts on the switch have continuity to each other when the switch is in the normal posistion. This allows the ground signal from the door switch to pass to one side if the lamp.

When the switch is moved to the opposite posistion it grounds the lamp terminal to the case of the switch completing the circuit to ground. If the switch does not have a good connection to ground it will not work.

I know my switch does not ground one terminal to the case. It is either bad or a different switch. I got the map light working with dome light and turn off with switch, i guess that is good enough for me.

 

[TrailBeast]

Assuming that '72 is the same as '74, then yes the switch is in the ground side of the circuit.

With the switch in one position the map light is connected directly to ground through the dash frame and turns on.

With the switch in the other position the map light is connected to the yellow wires of the dome light circuit, so the map light comes on when the doors are open or the headlight switch is turned.
QUOTE]

BINGO

 

[swifty]

If one terminal is grounded wouldn't the map light be on all the time? Or is there two poles in the switch that removes ground from the lamp terminal?

 

[1969383S]

There are two poles.

like said before the two terminals have continuity to each other with the switch in the normal position.

In the other position one terminal (brown wire) shorts to case ground and opens the connection to the second terminal (yellow door switch feed).

 

[swifty]

There are two poles.

like said before the two terminals have continuity to each other with the switch in the normal position.

In the other position one terminal (brown wire) shorts to case ground and opens the connection to the second terminal (yellow door switch feed).

You were right. I picked up another switch from a parts car and now the switch works like you said. I picked up a few other parts and when I opened hood almost had a heart attack. Two rabbits were under the hood and they shot out of there like a bullet. Was not expecting that! Anyway scored some parts and map light is working.:cheers:

 

[67Dart273]

So your old map light was a large part of the trouble?

 

[1969383S]

Glad to see you got it resolved!!

 

[RedFish]

So if I'm understanding all this, the map light can be left on to kill the battery ?
That was a typical fault for many years. Worst example I know of was mounted between the sun visors of a late 80s Mustang. Switch failure in those killed thousands of batteries.

 

[1969383S]

So if I'm understanding all this, the map light can be left on to kill the battery ?
That was a typical fault for many years. Worst example I know of was mounted between the sun visors of a late 80s Mustang. Switch failure in those killed thousands of batteries.

Yhupp....

Battery killer, but thats the way it was.

 

[Oldmanmopar]

It works on its own with the ground through the switch itself. I use to always drive with just the map light on. I just went through this on my duster it was the switch ground.

 

[swifty]

So your old map light was a large part of the trouble?

Yeah. The map light would only light with dome light. I had some other problem with dome light, bad connection by drivers side cover and a bad door pin. Both are working now. time to move on to glove box light and ash tray light.