Instrument and Panel Lighting - Questions/Guidance

[sdflysurf]

I'm working on my panel and upgrading the lighting.

Attached is a couple of pictures that have light wires connected to it.  Looks like part number 940012-501and not sure what that other black round thing is? (photocell??)

Found this description.  "Panel Light Control - 940012-501 - Replaces 800261 control and 914024-000 rheostat with new control panel lighting

"  and the black item has a wire from that grounding looking bus on the top to a ground terminal on the instrument panel.

Please let me know if you know about this setup.  Ultimately I have some lighting wires on my center stack equipment and JPI and HSI that I would like to land somewhere, and I would like to add LED strip in the glareshield.

[carusoam]

With part numbers on it... it looks official...

If it’s original... it probably won’t work very compatibly with LEDs...

New LED dimmers use a special electronic device to allow the LEDs to dim properly...

Old light circuits can often be used with LED as long as the LEDs have one regular bulb in Series...

 

Start with finding out what that box really is...? (How it is wired, what it is wired to)

PP thoughts only...

Best regards,

-a-

[sdflysurf]

All I could find is the part number on the box "Panel Light Control - 940012-501"

I can find nothing else anywhere.

[carusoam]

We can always ask @M20Doc... (updated M20F interior lighting and related electrical box question)

OP wants to connect dimmable Lights on additional equipment... including some LEDs...

• HSI
• JPI
• LEDs

 

Best regards,

-a-

[Guest]

I think the circular black piece is the fuel selector light, but it’s hard to tell from the picture.

Clarence

[sdflysurf]

Thanks @M20Doc I think you are right, that small round item is a light projecting on the floorboard for the fuel selector.  I'll check it when I power the airplane back up.  So that box 940012-501 is most likely the item "102 Control Assy" with 3 terminals.  I have not found the item "101 panel lite rheostat" on my plane - but I believe the "46 Instrument lite rheostat" is the round knob on the headliner that controls the adjustable beams from the headliner (pilot and co-pilot sides).

I did trace the compass light wire to that terminal 1 on the "104 terminal strip" - is that where I need to land my instrument lighting wires (for the garmin 430, kx125, stratus es, hsi, jpi, etc)?

Also if I wanted to add LED lights under the glareshield - how would you add this?  I would want to put it on a switch/dimmer.  Would its own breaker/fuse?  Would it be on the main bus bar or aux bus bar?

I'll look today for the "101 panel lite rheostat".

THANKS!

 

[carusoam]

My 65C got two rheostats... mounted in the ceiling...

• controlled all the panel lights and instruments...
• controlled the projector/spot lights from above....

In place of the various wiring locations of SDF’s box/bus....

The 65C had one terminal hiding under the pilots instrument panel, where all the radios, and instruments and post lights got their dimmed voltage from...

Interesting thing... the fuel selector light is just like the gear lights... twist for iris, push to test style.... this light is very close to the single point terminal....

If adding new lights... search around here for the LED lights and specific dimmer module type that is required... their current usage is quite low, they won’t be much of an additional load for any CB... probably best to be on their own CB...

PP thoughts only, not a mechanic...

Best regards,

-a-