Map Light Switch Location

[dstates]

Looking for your thoughts. This winter I’m installing new map lights (didn’t have them before). One on each side and I’ve chosen to use normal toggle switches on the panel to turn them on/off. There will be a switch for the pilot light and one for passenger light. Below are a few locations I could put the switches on my panel. Which location would you pick? Anything I need to consider. By the way, I’ll be installing a USB charger (GSB 15) in either spot A or B.

A - both switches far left. Plenty of room and easy for pilot to see and reach.
B - similar to A.
C - Slightly closer to passenger, no plans for anything else in the location in the future.
D - Easier for passenger to see and reach, but slightly behind yoke for pilot.
E - Split the switches and put the pilot side switch at location A and the passenger side switch at location E.

Thanks, Doug

[GAHorn]

Neither. I’d install a slide-switch on the door-post directly adjacent to the light.... so that each person could control their own light.

I’d hate it ...if I were the copilot... especially in a lighting emergency in the dark...to have to rely upon someone else to find that switch and get me some light.

[dstates]

Neither. I’d install a slide-switch on the door-post directly adjacent to the light.... so that each person could control their own light.

I’d hate it ...if I were the copilot... especially in a lighting emergency in the dark...to have to rely upon someone else to find that switch and get me some light.

I get that, George. I’m going to put your vote down as one on each side (A & E). I didn’t have any luck finding a slide switch that I like to go in the door post. The light I’m installing can be red or white so I need an On-Off-On switch and I chose to do that with an AN3021-1.
Doug

[hilltop170]

Doug
I mounted my pilot and copilot map lights on the front door post trim piece aimed at the panel in case I need light on the panel in an emergency. I also have post lights and some internally lighted instruments. I used the old-style pylon-mounted tube-shaped lights with the beam-adjuster knob on the back side with white lenses. If I was going to add lights today, I would probably use white/red LEDs instead of incandescent.

I mounted the on-off switches just in front of the ash trays located on the horizontal trim piece between the inst. panel and door post. They are easy to use.
Richard

[dstates]

Doug
I mounted my pilot and copilot map lights on the front door post trim piece aimed at the panel in case I need light on the panel in an emergency. I also have post lights and some internally lighted instruments. I used the old-style pylon-mounted tube-shaped lights with the beam-adjuster knob on the back side with white lenses. If I was going to add lights today, I would probably use white/red LEDs instead of incandescent.

I mounted the on-off switches just in front of the ash trays located on the horizontal trim piece between the inst. panel and door post. They are easy to use.
Richard

Richard,
That is definitely another option of where to put the switches. I am going LED. Below is what I’ve purchased from Aircraft Spruce and will be installing. My A&P/IA is comfortable with them.
Doug

[n2582d]

I didn’t have any luck finding a slide switch that I like to go in the door post. The light I’m installing can be red or white so I need an On-Off-On switch ...

Doug, As you know the door post fairing was where the switch was in the 1953 and on C-170's.

Screen Shot 2020-12-29 at 9.46.52 PM.png (45.67 KiB) Viewed 2677 times

A cursory look at the Mouser website shows several options for ON-OFF-ON slide switches. I'd use a DPDT switch to have one position for both the red and white lights and the other position just the red lights. The question I have is how deep of a space is there to mount a slide switch in the door post? Here's a couple of switches that would need around 1/2" depth. MS23AFW01 or GH49S010001

Switch with screw terminals.

[dstates]

I didn’t have any luck finding a slide switch that I like to go in the door post. The light I’m installing can be red or white so I need an On-Off-On switch ...

Doug, As you know the door post fairing was where the switch was in the 1953 and on C-170's.

Screen Shot 2020-12-29 at 9.46.52 PM.png

A cursory look at the Mouser website shows several options for ON-OFF-ON slide switches. I'd use a DPDT switch to have one position for both the red and white lights and the other position just the red lights. The question I have is how deep of a space is there to mount a slide switch in the door post? Here's a couple of switches that would need around 1/2" depth. MS23AFW01 or GH49S010001

Screen Shot 2020-12-29 at 9.30.22 PM.png

Gary,

I had looked at those specific switches. I don’t really like how the contacts would be pointing out from the interior panel towards the other wiring going through there. Just didn’t pass my smell test. Plus, I think there was an AD for that very issue on one of the Cessna models (I don’t remember the model or vintage). Plus I wanted something with terminal connections.

With that decision behind me, where would you recommend putting the switches on my panel?

Thanks for the info.
Doug

[n2582d]

Doug,
Good memory! AD 2001-23-03 is for C-172N aircraft. They were having problems with the switch contacts shorting out on the fuel lines going up the forward door post. The fix is to add a piece of plastic (for over $100) to insulate the terminals. Of course, unless you have a '48 C-170, there are no fuel lines running down the forward door posts.

I was going to suggest using the fixed piano key between the landing light switch and the nav light switch. It is an ON-OFF-ON switch but needs to be modified as explained here. I see though that you've already allocated that switch for your strobes.

Another idea would be to replace the overhead cabin light switch with an ON-OFF-ON DPDT switch and wire the overhead light to come on with both white and red map lights and use the other position for just the red map lights. This would eliminate having to add holes in the panel or trim fairings.

[hilltop170]

Doug
Those LED lights would be my choice if I was doing it today. Locating them on the door post fairing would still be my first choice but lower than shown in Gary’s attachment b/c up that high as-shown will interfere with the fresh air vent tube.

I always hate to drill more holes in the instrument panel but if you want the switches on the instrument panel and not on top of the side panels, I would mount them to the outsides and symmetrical with each other as much as possible just to look good, probably in your A position and the corresponding place on the copilot side.

Or, to keep from drilling more holes, I would move the mic jack back down below the headphone jack into the existing hole there and put the switch beside the headphone jack. That would be my first choice with corresponding positions on the copilot side.

[n2582d]

I second Richard’s suggestion of not adding more holes if possible and for keeping a symmetrical appearance. It looks like there are a couple of extra holes around the headset jacks on the left side. I also noticed you have pulled the parking brake cable which is good. However the hole there now looks like a kid with a missing tooth. One could fill the hole with a dummy knob like the one between the mixture and the carb heat. Or you could replace one or both of those spots with a pull switch for your map lights.

[GAHorn]

Unless the switch is placed immediately adjacent to the light.... good design would require a placard to describe function of the switch. (Think about the next owner...or an unfamiliar ferry-pilot needing to move the airplane.)