Kyle Wolfe wrote:George, when/if you pull the false instrument panel would you grab a few pictures of the lights and the plug in setup? Thanks!
Kyle, I have spanked myself several times for not taking pics when I did that mod. I can tell you, it’s not exactly a “work of art” to view.
But let me describe it in more detail:
I used 24 ga wire, twisted (such as when wiring a mag compass lighting) to avoid magnetic influence upon my panel-mounted mag compass.
I gang-soldered the GOR lamps to that twisted harness and insulated it with heat-shrink at the soldered connections.
Laying the false-panel upon my work table (Jamie fussed at me for using her kitchen for this project)... I routed the twisted wire pair around the backside of the panel and attached it every few inches using a hot-glue gun. At EACH instrument opening, arcing across the top of the opening, I installed the GOR lamps oriented Down so as to shed their light upon the instrument.. gluing each lamp by it’s twisted-wire to the panel. (Do not allow the hot-glue to contact the lamp itself.). The 3-1/8” gauges each got a triple-set of lamps about 1/2” apart around the circumference of the opening. The 2” instruments rec’d 2 lamps each. (This cut in-half the load thru each fuse...or said otherwise, doubled the protection for the circuit.)
I actually “split” the lighting into 2 circuits so as to reduce the possibility that a 1A fuse would blow in either 24 ga. circuit, and also to provide redundancy. I used a 1A in-line fuse for each.
I brought the long, twisted harness I’d made to telephone “modular” plugs so as to allow the circuits to be unplugged for the panel to be detached for maintenance. (In case I needed to remove the altimeter for recertification or replace a gyro, etc.) The telephone modular cord is also 24 ga and is the same as used on a typical ELT remote switch panel, so I had no qualms about using that method. The electrical draw/load is quite small (don’t recall the exact amount) but I tested it and found a 1A fuse would support it without “blowing”, and I wired it up in parallel to the overhead Grimes “torpedo” that Cessna provided for direct-instrument lighting.
The two modular plugs are connected to the output terminal of rheostat that controls the original overhead Grimes torpedoes.
Do NOT install any GOR lamps below instruments...only above them... or you will encounter glare as the light reflects off the instrument glass.
I have had absolutely NO problems with this system and No lamp failures. (They are rated for 20,000 hrs according to their supplier.)
Hope this helps.