Honda CB350 LED Diode Wiring How-To

In this video we make the diode wiring necessary for upgrading your vintage 1960s and 1970s Honda CB350, CB360, or CB450. This setup will work for just about any other vintage 12V motorcycle as well. This diode wiring is necessary when a single gauge bulb is used for the flasher circuit which is a very common setup on motorcycles of that era.
Installation: Connect the light blue and orange wires of the diode to the light blue and orange wires of the turn signal wires coming out of the harness. The pink wire of the diode connects to the "positive" side of the gauge bulb socket. Positive will be the wire that makes contact at the center pin of the bulb. The other wire on the gauge bulb socket makes contact via the side the bulb. This wire needs to be connected to ground (any solid dark green wire).
The Parts I Used:
18 Gauge Primary Wire:
www.delcity.ne...
1N4001 Diode (x2):
www.amazon.com...
3.5mm Male Bullet Terminal + Insulator (x2)
www.vintageconn...
3.5mm Female Socket Terminal + Insulator (x1)
www.vintageconn...
8 AWG Insultherm Tru-Fit Braided Fiberglass Sleeving (Optional)
www.wirecare.c...
Heat shrink tubing
Soldering iron, solder, etc.

[@jethroseghers9353]

Wish I saw this sooner, wasted some good money on some junk diodes with tiny wires. A++ ... Thanks

[@michaelsams450]

Thanks for watching!

[@surfmoto]

EXCELLENT video. Going to use this to fix my DR650 now. Thanks!

[@michaelsams450]

Glad it helped. Thanks for watching.

[@PalavraVivaUSA]

so satisfying :)

[@frydaddy1984]

What size diode do I need? Do you have a link to where you purchased it? I have a 2009 vstar 650 with 4 1157 bulbs. All 4 Marker lights come on with key. Thanks for your help.

[@michaelsams450]

I used 1N4001. There is link to diodes I purchased in the video description.

[@HB-yq8gy]

Thank you great video. I'm trying to find a video for LED conversion for the 1993 CB750. My bike turn signals has 2 blue wires 1 green ground & 2 orange & 1 green for ground. How do you wire the diode with running lights? I find the wires for the signal indicator. Do you need a diode for each side? Meaning running lights & turn signals?

[@michaelsams450]

The diode is necessary on the older bikes with a shared indicator in the gauge cluster. Depending on your bike's wiring it may not be necessary. A wiring diagram will be a big help. The CB360 had running lights, you might try to find a video or forum thread detailing the conversion of one of those to LED.

[@jacksnyder4708]

So this if very timely. I have a stable of vintage hondas, 1968 through 1975 and am in the process of upgrading to LED across the board. Went after my CL450 turn signals today for starters, upgraded to LED flasher etc, but when I install all four LED amber lights, I get all four lights responding instead of left or right. It's like a four way flasher. Works fine with one LED and one incandescent on left and right. Is this diode setup the cure for that? Not sure how it's bleeding across all four circuits at the switch.

[@michaelsams450]

Yes, this diode setup is the cure. From my understanding the problem is due to the fact that LEDs are themselves, diodes. So the current can only flow through them in one direction whereas traditional incandescent bulbs allow current to flow in either direction. I'm sure there's a more technical explanation out there but this setup fixes the issue.

[@jacksnyder4708]

@@michaelsams450 So based on the other video, you run the combined diodes through the orange wire going to the amber gauge light and the light blue from the gauge light goes to ground. I can't tell you how much I appreciate you taking the time to share this info.

[@michaelsams450]

@@jacksnyder4708 In most cases, yes. The combined wire (pink in my example) needs to go to the positive connection (bottom) of the bulb socket which from what I can tell after doing this on a few bikes is the orange wire coming from the gauge light socket. The other (light blue in this case) goes to any available ground terminal. So far I've only done this on a couple of 350s and a 450 so I can't confirm beyond that.

[@ILikeRice0KSTFU]

Just found this, I had a spare pair of 1N4007 could I use those??

[@michaelsams450]

I think so but you should look up the specs for that diode model to be sure.

[@irishrider7324]

Where is part 2??? The installation?

[@michaelsams450]

This video was actually a supplement to the LED conversion video I did. Installation is pretty straight forward: The combined wire (pink in my example) needs to go to the positive connection (bottom) of the bulb socket (on CB350/CB450 usually the orange wire coming from the bulb socket). The other wire coming from the bulb socket (light blue in this case) goes to any available ground terminal. The light blue and orange coming from the diodes plug into the respective terminals on the harness (where you unplugged the bulb socket wires from).

[@samuelward8809]

I have a Cb125 1980 , would I need to do this for my bike aswell , runs on 6v battery .

[@michaelsams450]

I would imagine so but I've never worked on that bike so I would suggest referring to a wiring diagram for your bike before making any alterations. On older 6V systems there is often a separate circuit to power the headlight and in some cases a separate "lighting coil" altogether. On top of that, some bikes use the AC current coming directly from the stator/lighting coil to power some of the lights, and DC from the battery for other lights. Again, check your wiring diagram. The diode sub-harness is necessary when converting some older bikes from incandescent bulbs to LED bulbs because electrical current can only pass through a LED (Light Emitting Diode) in one direction, it's a diode after all. The diode sub-harness prevents the current from one leg of the turn signal circuit from back-feeding into the other. With traditional incandescent bulbs the current can pass in both directions. I wish I could give you a more definitive answer but my wiring experience is limited to Honda motorcycles from the 60's and early 70's. I haven't messed with my '82 C70's wiring and it is still running incandescent bulbs.

[@Icanreadgood1]

One question, I need to install this diode kit on my 2012 shadow phantom. Do you know if it will interfere with the daytime running lights or is it the current is only separated when the turn signal is activated?

[@michaelsams450]

I can't say for sure, I'm not familiar with that bike's wiring setup.