LED Lighting for Ritchie Compass

by Chris Stewart

While checking my binnacle compass yesterday on “24~7”, my Catalina 36 #251, I found that the little red bulb was burned out. Going against the thought of "don't fix it if it ain’t broken," I thought it might be an interesting project to replace the old bulb assembly with one or more red LED lamps. LED lighting should last longer, use less energy, and give better/more light on the compass.

Granted, I could buy a replacement bulb for a couple of bucks, but what fun would that be? And on a positive note, what a great way to learn how to make your own LED fixtures for a fraction of the cost, and better fill your lighting needs?

I removed the black plastic trim piece on the top rear side of the compass housing, and carefully removed the two metal brackets and screws that hold the bulb. I cut the two wires, leaving enough remaining to be able crimp a new assembly into place. I put the pieces in a zip-lock bag for storage in case the LED's don't work.

I purchased a single red 12v LED lamp like you would put in your instrument panel. The problem I found with this is its size: it is about 1/4" in diameter, about 1" long, and the light is concentrated at the end of the LED. I needed a lamp that will direct its light back towards the compass. The LED I had was easy to wire, and it did fit sideways into the plastic trim piece. I tested the light, but found that it didn’t light the compass as well as I would like. I thought that a second same LED might work if I put one at each end of the plastic housing.

As a side note... while I was at it I wired in a waterproof disconnect, making it easier to remove the compass and light as a unit. With the original set up you had to hang the compass housing off the binnacle while you were working on it, or remove the light and wiring assembly.

New Lamp Connector

Online I found a great DIY page that gives you the info you need to make the unit. (http://www.ehow.com/how_4480452_wire-led-lights.html). At the bottom of that page was a calculator to determine what size resistor you need to connect in series with the LED (http://ledcalc.com/#calc).

All I had to do now was to figure out what LED would give me the amount of red light I needed and determine if it will fit in the plastic trim piece, and then to figure out how to secure the LEDs, wire and resistor inside the unit.
At West Marine a day or so later I found a LED Dual Mount Light with three red LED's. It cost about $10.00, and it looked like it would be the solution to my project. The two outside red LED's aim outward at about 45 degrees, and the middle red LED aims straight ahead. (The WM product number is #9265919)

Using the Dremel, I cut off the two end tabs and shaved the back of the case to fit the round compass light case. I temporarily secured the light in place with a couple of small Velcro tabs. After installation I checked the lights with a 12v source to make sure they worked. So far, so good. Now all I have to do is go to the boat and see if it all fits...

On the boat now, the new LED lamp is in place and operating. I had to make a few more Dremel adjustments, ie: shaving the plastic case down to help it fit into the plastic housing. Because I had to shave off part of the case, I sealed the back, which was exposed, with some silicone sealant.

After Dremel Shaping

The light does the job just fine now, and according to the manufacturer the LED's will (theoretically) last a lot longer than a light bulb. I did a little night simulation with a towel over the compass. It looks like it will be much easier to read the compass now, with three lights rather than one.

Would I do it again? Well, buying the little light bulb would have been a lot easier, and with little or no hassle...but what fun is that?

New Lamp Checks OK