Mike Spera wrote:
The 2 VOR/ILS indicators are internally lit as is the VC compass and
clock. These are all running off the one lone factory dimmer. On full,
the indicator lights will illuminate the cabin, so I run them way down
at night.

I wonder if it would be possible to install lower-wattage lamps in the
VOR/ILS indicators, or install a (fixed) resistor or diode in series
with the existing lamps in the indicators. This would let you turn the
dimmer knob up higher and have more light on your other instruments,
without the indicators blinding you.

A fixed resistor can be sized to give you pretty much whatever voltage
drop you want. You'll probably need a "power" type rated for at least
a few watts, and it needs to be mounted where it can get hot. If you
really want to be fancy, get one of the ones that comes in a finned
aluminum case with mounting lugs so it can be bolted down.

A diode will drop something like 0.6 V to 1 V; you can use a few in
series to drop more voltage. It will also get warm in use and needs to
be mounted where this isn't a problem. The most common diodes (1N400x
and 1N540x rectifiers) are just a lump with two wires sticking out like
a resistor. You can get diodes in TO-220 transistor cases with a
mounting/heatsink tab but these are not as common.

Can I glue in some bulbs to the plastic overlay and have a dimmer
controls running to the cig lighter?

I don't know if it's legal but it's electrically possible. All the
dimmer should need is 12 V and ground. You may want to make sure that
the plug you use fits the lighter really well.

If it's mechanically possible, you might consider the cig lighter plug
for your other options as well. Install the new lamp securely but
temporarily and wire it to a dimmer which then plugs into the lighter.
If you like it, you can get it wired more permanently.

Matt Roberds

Disclaimer: This is based on experience with illumination in ground
vehicles and in fixed installations. I don't have an A&P; I don't even
have a TG&Y. Some of this may not be allowable owner maintenance.
Your mileage may vary.