MOPED ARMY

Here is a 1980 Honda Express NC50 Wiring Diagram (pg. 29-10).

Here is the rest of the 1977 - 1981 Honda Express Shop Manual.

If the brake light blinks a little bit with the signals, that's normal (my 1981 NC50 does the same), because it's a 6V system, and it doesn't have that much power. Urban Expresses and Express SRs had 12V systems later on in 1981-83.

You might want to get some halogen turn signals (very bright), a 12V car taillight (works perfectly and easy to find, and I think the one I have is a 1157 taillight), and a removable headlight bulb assembly (not sealed beam) if you don't have one already. No special bulbs are needed for the signal and high beam indicators, and the speedo, just the generic ones (look for the number on the bulb).

Also, if you don't have a new battery, get one. If you don't have a good battery, you can blow the headlight and the other lights won't work right. If the fuse is damaged, got a new one. The battery is the regulator, so if it is weak or dead, there is nothing to regulate the amount of power going to the lights, which means they get surges of power way greater than 6V and blow out. And lastly, make sure all the wire connectors are in securely. My turn signals and ignition switch wires came out at one time, causing them not to work.

I hope this helps quite a bit!

~Adam

I would say get a new flasher. My grandpa found an old Volvo 6V flasher can in his barn. Works and fits perfectly, and you can hear the flasher clicking while the engine's running. Probably something like this flasher would work. But you'll have to find out which two prongs make the lights flash. Pretty much any flasher can that's 6V would work.

Do you have the stock airbox, aftermarket air filter, or none?

~Adam

You should get the 6 Volt tail light bulb, thats what is supposed to be there. Your blinkers wont continuously blink if you just have the key on. The engine should be running and charging the battery. You will notice as your driving the blinkers will work just fine. I have 3 NC50s a 78, 80 and 81. I had to bring them all back from the dead, and all of them had wiring issues I had to deal with. They all work perfectly now after many head scratching nights. I will also reccommend the replaceable headlight bulb option a previous poster mentioned, well worth it. ALL the bulbs should be in and working so you dont blow the bulbs one by one. I have a very cheap alternative for the little instument bulbs too if you need them, just let me know. Oh yea, I got the 6 volt 1157s from NAPA. ? Go figure.

Yo! I made a video of the turn signal wiring on my Express. Mine is a 78, but wired like a 1980 with 4 signals. The first post of mine in that thread has a color coded wiring diagram that may also help you. Are you using a 4 amp hour battery? Be sure to check that. The turn signals on my bike DO blink when it is idling, and the whole system is 6V. A weak battery could cause them to stay on solid, and might make your tail light not come on 'bright' when you brake as well. Also, I had a problem just this week with the signals on the left side not blinking. It turned out that one of the little plug-in connections near the tail was loose. Plugged 'er in all the way, and BAM. Blinking again. Good luck to you! Here's a LINK to the wiring video.

Sorry I should have said all this already, but I replaced the battery with a brand new one when I cleaned everything out and got it running. Also I had to buy a new headlight and ring off eBay. The person who I bought it from already changed it to be able to remove the bulb. I am still confused about the whole brake light problem. I watched the video which helped and made sense about the wiring. I might try a new relay. Nothing on this bike has been changed since it was made.

What exactly do you mean inside the brake levers on the handle bars. Where exactly are those at? Can you tell me what the other colors do for the brake light? I tried to unplug them and they didn't work when I unplugged the green one. I think that is the ground wire, but I'm not 100% sure.

I think what Mel is talking about is a little black button type thing behind the brake lever. If you pull the left/right brake levers back, and look behind it near the brake cable, you'll see a little black plastic button. When the brake lever is not pulled, the button is pressed in, not allowing the brake light of the taillight to illuminate. When the brake lever is pulled, the button is not pressed in, causing the brake light of the taillight to illuminate. I attached some pictures of the button: a close up, one from underneath, and one from the side farther away. Maybe yours is stuck in, not allowing it to get bright when pulling the lever. Check this on both levers.

~Adam

Sounds good I really appreciate all your help! It has been very helpful! Has anyone ever put on an aftermarket air filter? If you have I am wondering which works best or if it is even worth it.

In the attached pic, this is the air filter that was on my Express when I bought it. It's a K&N metal mesh air filter. My advice is that you get one that has a foam outer filter and not a metal mesh thing like this, because you can clean the foam ones way easier. Now I have an original 1981 NC50 airbox.

~Adam

i found the craziest thing at home depot...a lawnmower generic aircleaner you know the ones that have the long screw that goes in carb hole on lawnmowers. Anyway its almost dead on dimensions as stock box. Would have to some engineering but its a foam filter...only issue as it's 100% enclosed I dont know what to do as far as air input....cut some grooves? big circle hole?

Briggs & Stratton air filter