Map Light Questions

[GregP]

I'm working on the map light in my 73 240z. The one in there was working but not now. It may be a replacement housing as the 2 wires (red & black) are spliced in. I am going to replace the bulb but the more I look at it the more questions I have.

Does the map light have continuous power going to it through the red wire? 

Does it have its own line fuse? Mine does not have any power in the line even if I have the key on or lights on.

Is the housing supposed to be black? Mine is white.

Thanks!

[SteveJ]

The stock circuit has a red/blue wire and a black wire. The red/blue comes off the fuse for the dome light. It is always hot.

The map light housing is white.

[GregP]

When you refer to fuse for dome light is that in the fuse box or a separate inline fuse? Dome light also stopped working. I don't have the red/blue wire but as you can see there have been a few splices into the line. I'm wondering if I can just tap into the continuous power line from the hazard or something else. 

Also is this the right map light bezel for a 73? 

[SteveJ]

9 hours ago, GregP said:

When you refer to fuse for dome light is that in the fuse box or a separate inline fuse?

Fuse box. If you don't have a cover on your fuse box, copy the picture below to your computer and consider printing it:

Or this:

9 hours ago, GregP said:

I don't have the red/blue wire but as you can see there have been a few splices into the line. I'm wondering if I can just tap into the continuous power line from the hazard or something else. 

What I see in your photo is that someone put on some butt splices to connect wires. Unfortunately some people hack into wiring harnesses like that. You could tap into another circuit, but since you don't seem to have much electrical knowledge, I suggest you don't. Most people don't know how to splice into existing circuits properly, and that causes more issues. It's kind of like the problem you have now. Amongst other problems you can create is that you could cause a fuse to blow more often if there is more of a load than the circuit was designed for.

The First Rule of Holes: When you want to get out of a hole, the first thing you should do is stop digging. There are references in the downloads section that include a PDF of the factory service manual. The BE section has some good information on the electrical system. If I can remember, I'll also upload a clean scan of the wiring diagrams I did from my copy of the FSM.

Diagnose the circuits. Do you know how to use an electrical meter? If not, find some Youtube videos to start learning. Today is a great day to learn something new.

9 hours ago, GregP said:

Also is this the right map light bezel for a 73? 

You don't have a bezel. Here's the bezel: https://zcardepot.com/products/map-lamp-light-bezel-240z?_pos=1&_sid=bd9927824&_ss=r

My guess is that you're also missing the screws. https://zcardepot.com/products/map-light-bezel-screw-240z

Keep posting photos with your questions. It does help in composing responses. 

[GregP]

Thanks Steve! That was a big help. Got everything working and just have to tackle reconnecting the heater control cables. Such a simple job but need two hands and hardly any room to maneuver.

[Richie G]

@SteveJ that fuse box picture describing the actual uses, when voltage applied, etc. of each fuse is awesome.  i have an early 71, would wiring still be the same?  I've never seen it so simply explained before thanks!

[SteveJ]

11 minutes ago, Richie G said:

@SteveJ that fuse box picture describing the actual uses, when voltage applied, etc. of each fuse is awesome.  i have an early 71, would wiring still be the same?  I've never seen it so simply explained before thanks!

I don't know if the 71 had the seat belt warning. I think the headlights may have constant voltage with the headlight switch completing the ground path. In the 72 & 73, the headlight switch connected the positive with the fuse box with a red wire.

There may be some other differences that I haven't tried to determine.

[SteveJ]

I finally remembered to upload the wiring diagrams from the FSM. There are some errors. The intermittent wiper relay wiring is wrong on the diagram. The 74 manual corrected the errors. I can't recall other errors off the top of my head, but Matthew Abate and I were running across them as he tried to rebuild his wiring harness.

73 Wiring Diagrams.pdf

[Richie G]

17 minutes ago, SteveJ said:

I don't know if the 71 had the seat belt warning. I think the headlights may have constant voltage with the headlight switch completing the ground path. In the 72 & 73, the headlight switch connected the positive with the fuse box with a red wire.

There may be some other differences that I haven't tried to determine.

You're right, no seat belt light and i notice choke light which isnt in the 71 either.  thanks for the quick response and great work as always.