Dome Light ?s (1 Viewer)

[AdamKFarmer]

So, my 40's ('82) dome light has never worked since I owned it. It looks fully operational just isn't wired correctly. I have attached a few pictures and the schematic snippet. The wiring diagram really doesn't explain how the light works in conjuction with the door opening and closing. I assume the door provides a ground through the (red?) wire because that is the color coming off the door switch. The other (green?) MUST be the 12V supply coming off the harness. And according to the schematic it is wired into the tail light fuse.

1) Does my logic seem sound? The toggle has 3 positions, on/off and door. The on seems to ground through the screw and off isolates it, which leads me to believe the door grounds it through the red wire.

2) Where can I get connectors like these? Someone mentioned bullet connectors but I don't see those working. Thanks!!

 

[AdamKFarmer]

Additional picture attached.

 

[Pearly]

It just has a constant 12V (Green wire), switched 12V (Red wire) + ground through the screw to the door frame. The constant 12V goes to the manual switch at the bottom. You should have a normally closed switch (12V) when the door is open and opens (0V) when the door is closed.
Check 12V to the Green wire. This is the same circuit as the inspection socket in the glove box, so check that you have 12V there too.
Check 12V to and from the door switch on the Red wire and then up the cable.
The cables can get broken when the hard top comes off.

In your photo, the switch is OFF - pointing to the ground, so the bulb is powered via the door switch (Red).

I've just flown back from Hong Kong and on my second whisky, so correct me if I am wrong!

 

[myquestoyota]

It actually has a door switch?

 

[Living in the Past]

It actually has a door switch?

Door switches started with the 82 model. Front doors only.

 

[Living in the Past]

In this picture Red appears to be + and always hot to the lamp. The green wire goes to the doors switch and makes to ground when the bottom pops out when the open and the switch is on door. On the "ON" it makes ground thru the screw. If you top is no making a good ground the lamp will not work. Even that screw could have a ground problem.

 

[AdamKFarmer]

Yeah, both front doors do. I see! I have an '82 wiring diagram but it's at the house, the only one I have a digital copy of is the '81, (which is what I provided). Neither wire was hooked up at all, so I need to run both at some point. What are my options with the connectors?

 

[myquestoyota]

Door switches started with the 82 model. Front doors only.

Anyone retrofit one to an older model? I was just thinking about it the other day but didn't know any 40's came with one. I already have an led in my dome light but the switch is just a stub, it came that way. A door activated light would be a nice addition in these dark days of winter.

 

[AdamKFarmer]

Agreed. That is why it's my current project.

So, LITP, I think you may be right. But I swear the red wire is coming off the door switch.. humm multimeter time! I'll report back with my findings.

 

[Fast Eddy]

It would be neat to do a retrofit with a little microswitch up at the top near the light. Maybe just hot-glued to the door frame?

 

[Pearly]

In the cold light of day, if the wiring diagram matches your car, it would appear that the Red may be a switched Ground - grounded when the door is open (door switch makes the circuit) and open circuit when closed. This would make the Green 12V live and the lamp switch just turns the lamp OFF all the time or ON when the door is open. So to confirm this, use a meter, measure the current and continuity on all points - Green wire to Ground, Red to Ground, Red to Green, Red to door switch, door switch to Ground and see what's what.

 

[Pearly]

Another one...

https://forum.ih8mud.com/40-55-series-tech/491812-dome-light.html

 

[Weber Sarge]

Almost all dome light circuits are grounded at the door switches , dome control or lamp itself to allow multiple spots to make the light work . I'd like to see what type of door switch was used on the later models - these doors have a lot of adjustment/play to them .
Sarge

 

[Pearly]

It certainly makes more sense (safety wise) to have the light grounded through the switch.

That would confirm that you Green should be the 12V, if the Red goes to the switch. One side of your door switch would be Ground, the other would go to the lamp.

 

[Weber Sarge]

The ground circuit is sort of a daisy-chained setup - a single ground wire just runs in series through all door switches and if grounded anywhere along that path it will close the circuit .

Anyone got a pic or part number for these door switches ??
Sarge

 

[AdamKFarmer]

The ground circuit is sort of a daisy-chained setup - a single ground wire just runs in series through all door switches and if grounded anywhere along that path it will close the circuit .

Anyone got a pic or part number for these door switches ??
Sarge

Sarge- Here is a picture of my driver's side door and the back side of it. Please excuse the cell phone pictures

So, great news! the two wires in the picture are the red and green wire right off the harness Myself and the multimeter verified 12V on the green and a ground on the red when the driver's side or passenger's side door is open! So, everything is in working order I just need to run the wires to the light! Will post with final results soon!

 

[Pearly]

Hey, that's great news - and thanks for reporting back. I actually didn't know that there was a door switch on the later 40's until reading your post!

 

[Weber Sarge]

Ok , that's what I figured - a spot-welded bump that holds the switch . I couldn't picture Toyota using a long-barreled switch for these doors but who knows . That spacer makes the switch work smoother so it isn't "sliding" against the door , instead it just moves a bit in and out to make contact . Retrofitting a switch on an older 40 isn't going to be that easy due to that extra piece of sheetmetal . Unless someone wants to replicate a bump-out with a die press .... ?
Sarge

 

[myquestoyota]

Can you measure the height of that bump? Shouldn't be too hard to fab something up if someone wanted to.

 

[AdamKFarmer]

Can you measure the height of that bump? Shouldn't be too hard to fab something up if someone wanted to.

Yeah, I"ll see what I can do.

Got it all wired up last night and learned a few things. Looking back at it again it's pretty straightforward that the RED wire needs to be the 12V and the green needs to be the door ground. The reason this was so obvious to me, was that after wiring this all together only the selectable door option was working. This has to do with the physical geometry of the plug wiring. When the red is the ground it only allows the 12V to energize the light at the door selection and when it is trying to ground through the screw it doesn't go through the bulb. I just used 14 ga wire and bullet connectors, I hated to cut off the old harness connecters, but I didn't see any other option. Fishing the wires through the windshield frame was the most difficult part of it all.
Hope this helps someone down the line.
I really dig the "yellow" light this bulb produces, perfectly in line with the old cruiser.