CB550 LED Upgrade continued - License plate

When upgrading the tail light on the CB550 from the stock incandescent to a red LED, I lost the legally required white illumination of the license plate. The bottom of the tail light lens has a clear section that originally allowed the white light from the incandescent lamp to illuminate the license plate.

While searching for a solution, I came across these cheap, all-metal white LED bolts:

The price was right at less than $4 with free shipping. They took just over a month to show up, but I didn't mind the wait.

Installation was straight-forward. The tail light wire on the CB550K is brown, and this wire always has voltage on it. The green wire with the yellow stripe is for the brake light, and the solid green wire is ground. I just stripped back the insulation on the appropriate wires and soldered on the leads from the LED bolts. Care needs to be taken to make sure you have everything already over the wires, as once they're soldered, you won't be able to get any nuts or washers over the studs. That might be the only drawback to this style of light, but I don't think I'll need to take the license plate off for quite some time.

The other thing I did was place some foil tape on the inside of lens to block the red light from bleeding onto the license plate:

And the finished product:

CB550 LED upgrade

Having recently taken the CB550 out after dark a couple of times, I realized the 1970s stock lighting was in need of a bit of an upgrade.

I replaced every single incandescent bulb on the bike (with 2 exceptions, noted below) with LEDs from superbrightleds.com.

Here's what I ordered.

Idiot and gauge lights:

• Oil - (1) LED BA9S-R-120-12V: Red 120 Degree 12V
• Neutral - (1) 1 LED BA9S-G-120-12V: Green 120 Degree 12V
• High Beam - (1) 1 LED BA9S-B-120-12V: Blue 120 Degree 12V
• Turn Signal - (2) 1 LED BA9S-A-120-12V: Amber 120 Degree 12V
• Guage lights - (4) 4 LED BA9S-G4-90-12V: Green 90 Degree 12V

Marker and brake lights:

• Brake - (1) Dual Intensity 45 SMD LED Tower 1157-R45-T: 1157 Red
• Front turn - (2) Dual Intensity 2 Watt Adjustable Right Angle 1157-A2W-ARA: Amber
• Rear turn - (2) Single Intensity 2 Watt Adjustable Right Angle 1156-A2W-ARA: Amber

I forgot to order a new neutral LED in the first order, so the neutral you see in the pictures below is still the old incandescent. Also, one of the 4-LED bulbs intended for the guages broke, so I need to order another one of those. The 4-LED bulbs definitely provide better illumination of the guages. I doubt the single LED version would provide sufficient light output for them.

The high beam indicator is much more noticeable now, but it could still be brighter. I'm going to try the 4-LED variant of the BA9s next and see how that works.

Instrument and idiot lights before.

New instrument lights on the left. Old on the right.

New idiot and instrument lights.

For the turn signals, I chose the new right-angle adjustable single-LED 1156 and 1157 models. These have a wide-angle lens LED mounted inside a large heatsink, followed by a small diffuser lens to even out the light. These worked well, though the small tabs that lock the light into various angles of rotation broke when trying to push and rotate the light into the socket. The blinker relay had already been replace with a solid state module by me during the restoration last year, so the system was already more or less LED ready.

Another thing worth mentioning is that I had to disconnect the turn signal buzzer in order for the turn signals to blink correctly. With it still connected, both the front and rear lights would only partially blink. I'll have to decipher the schematic later to find out why that's the case. 

Old on the left, new on the right.

Front marker and tail light.

The other noticeable improvement came about with the 45-LED tower 1157 bulb I chose for the tail light. This bulb is at least as bright as the stock 1157 when on low, power, but much brighter when you apply the brakes.

The only downside is the stock, clear 1157 is intended to provide light for the license plate through a clear portion of the tail light lens. With LEDs, you want to match the color of the lens when purchasing them, otherwise you will be wasting light output when passing through the lens.

So, without changing anything, the license plate is now lit with red light, which violates PA DOT license plate lighting requirements. I intend to fix that with a pair of white LED bolts and some foil tape over the clear portion of the tail light lens.

Tail light.

Brake light.

Rear turn signal.

All in all, it cost about $100 to replace all of the lights with LEDs. This should result in significant power savings and less strain on the charging system, which still needs some adjustment.

Next I will be replacing the stock sealed-beam 45W headlight with a Bosch H4 conversion reflector and a 55W/60W modern-day halogen bulb and some direct wiring from the battery to minimize losses. Between the LED upgrade, some wiring upgrades for the headlight, and a properly adjusted charging regulator, I should have much better lighting than stock and no problem keeping the battery charged, while still retaining that stock factory look.

Edit (Apr 29, 2016):

Here is a quick analysis of the current/power draw before and after, and some conclusions.

Unfortunately, I never quantified the current draw before and after by measuring.

But, we can estimate it thusly:

Before (worst-case, all lights on):
- 9x BA9s indicator lamp, 0.24A = 2.16A
- 3x 1157 dual filament (brake, rear running light, front marker, front turn), 3*(2.10A + 0.59A) = 8.07A
- 2x 1156 single filament (rear turn) = 2.1A = 4.2A

Total before with all lights on: 14.43A = 61W @12V

After (worst-case, all lights on):
- 1x 1 LED BA9S-R-120-12V (oil) 0.019A
- 1x 1 LED BA9S-G-120-12V (neutral) 0.018A
- 1x 1 LED BA9S-B-120-12V (high beam) 0.018A
- 2x 1 LED BA9S-A-120-12V (turn signal indicators) 0.021A = 0.042A
- 4x 4 LED BA9S-G4-90-12V (gauge illumination) 0.029A = 0.116A
- 1x Dual Intensity 45 SMD LED Tower 1157-R45-T (brake) 0.150A
- 2x Dual Intensity 2 Watt Adjustable Right Angle 1157-A2W-ARA (front turn/marker) 0.165A = 0.330A
- 2x Single Intensity 2 Watt Adjustable Right Angle 1156-A2W-ARA: (rear turn) 0.165A = 0.330A

Total after with all lights on: 0.858A = 10.296W @12V

Obviously there are no states in which all lights are illuminated, so the above figures are truly worst-case. It's obvious to me that the biggest savings are realized when replacing the front marker lights, tail light, and gauge lights, as they're always on. If we look at replacing just those, we go from 9.03A to 0.431A. The rest of the lights are worth replacing anyway, especially the idiot lights as the LED equivalents tend to be much brighter than their incandescent counterparts.