LED Headlight on a P11

[Schwany]

Nothing new for a Norton or any motorcycle, but I put a cheap LED headlight on my RestoMod P11, cuz I wanted a LED ring light like many fancy cars are sporting. Being a lazy simpleton, I did it the goofy way and left the bike Positive earth. When doing it that way all I get is one light switch, since my switch is all polar Negative. Once the key is switched On Negative is always present at the light. The LED headlight can only be switched Positive polar. The LED headlight has a running light ring, low beam, and high beam, and no other fancy colored lights or blinker function. To use all three of the lamps separately, I would have to install 2 more Positive polar switches, or convert the bike to Negative earth, and install one extra switch. So I turn on the running light ring and the low beam at the same time by having two separate wires running to Positive ground. Would be difficult for on coming traffic not to see this headlight, since it is bright white light. I bought a overpriced reverse polar LED tail light, so I won't be converting to Negative earth any time soon. However, I'm sure I will eventually.

BTW the only reason it works at all without becoming a big dead short is the cheap LED headlight is rubber mounted and the enclosure is electronically isolated from the ground.

This is it ignition off.

Light On image with 2 stops of negative exposure. Otherwise, the image is just a big over exposed mess where the light is.

 

[batrider]

I can see an electrical fire in your future. You are flirting with disaster with a hot headlight shell.

 

[Schwany]

I can see an electrical fire in your future. You are flirting with disaster with a hot headlight shell.

I think you need a new crystal ball.

The headlight shell is not hot, it has no polarity at all. The LED electronics are isolated from the shell, and the shell is isolated from the headlight mounts and chassis ground be it positive or negative. Only way it could short is if the insulation on the negative wire heading to the headlight from my ignition switch wore through and the wire shorted against the positive grounded frame just like it would if the headlight was a standard positive ground headlight.

I'll probably switch to negative ground soon so I can support the ring light separately from the low beam on the ignition switch. The headlight electronics will still be fully isolated, I'll just have a little more functionality at the switch.

I'm also running a LiFePO4 battery. I already know how scary that is for members here. Still waiting for that predicted fire to happen.

 

[Deets55]

I think you need a new crystal ball.

The headlight shell is not hot, it has no polarity at all. The LED electronics are isolated from the shell, and the shell is isolated from the headlight mounts and chassis ground be it positive or negative. Only way it could short is if the insulation on the negative wire heading to the headlight from my ignition switch wore through and the wire shorted against the positive grounded frame just like it would if the headlight was a standard positive ground headlight.

I'll probably switch to negative ground soon so I can support the ring light separately from the low beam on the ignition switch. The headlight electronics will still be fully isolated, I'll just have a little more functionality at the switch.

I'm also running a LiFePO4 battery. I already know how scary that is for members here. Still waiting for the that predicted fire to happen.

Since the bulb/lens is completely isolated a couple of relays might solve your problem without going to the trouble of a complete conversion.

 

[Schwany]

Since the bulb/lens is completely isolated a couple of relays might solve your problem without going to the trouble of a complete conversion.

Converting my '67 P11 to negative ground isn't a big task. I just didn't feel like doing it when I put the headlight on. My P11 is wired like a dirt bike with a head light and a tail light. Ignition is Boyer, Coil is dual output, R/R is Tri-Spark. Adding the relays would be more work than converting it to negative ground. All I really need to do is move a few wires around. The relays would require more fiddly wiring. Good idea though.

The easiest thing to do would have been leaving it alone.

 

[batrider]

Ok sorry to freak out. Clear to me now.

 

[Schwany]

Ok sorry to freak out. Clear to me now.

No big deal. I'm accustomed to members here trying to prevent me from hurting myself. I color outside the lines a lot.

It was really a proof of concept project. If I could not have made it work, I was going to replace the sealed beam with a H4 style enclosure and put a H4 compatible LED lamp in it. But I got a wild hair up my arse to put a ring light on. It works great so far with the ring light and low beam on at the same time. Cars getting ready to come out on side streets waited for me to pass today. I'm sure somebody who obviously owns the road will eventually pull out in front of me, but I'm liking how annoyingly bright it probably is.