1982 Honda Express NC50 wiring short (can't find it, please help)

The bike starts and runs fine so I believe this issue is isolated to the lighting wiring. When I connect my 6v battery leads, the wiring immediately starts to get hot if I have the key on. With the key off this does not happen. It seems to be linked to the black wire that comes off the 4 way connector at the handlebars that goes through the frame however the only place I see a black wire coming out of the frame on the other end goes to the blinker relay. I've tried connecting the battery with the CDI unit, blinker relay, silicon rectifier and all engine wires disconnected and still get hot wires. I've checked that the silicon rectifier only has continuity in one direction, I've checked that the key switch functions properly, I've checked that all the handlebar switches appear to be functioning properly inside. I've checked turn signals for shorts. The brown lead to the tail light is grounded to the chassis....should this be?

I should also mention when I got this bike all the wiring appears to be in its original factory unmolested condition with no patches breaks tears repairs etc. I do have the wiring diagram for this bike and have reviewed it extensively and I still cannot find the source of my problem. All light bulbs were removed from the bike with the exception of the non removable odometer bulb. All the bulbs were blown except one blinker on each side of the bike (one in front and one in the rear)....odd but that's likely due to the bike having been run with a dead and or missing battery. I also checked the turn signal terminals for shorts and don't see any. I also checked the coils and their resistance values seem to match that of my step brother's bike. I've had this problem with this bike for years and I can't seem to sort it out and I would love some ideas/pointers if anyone might have some thoughts on things to check.

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

82 was still 6V? Sounds like battery might be shorted . Have you checked it?

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

82 was not 6v, you have the wrong battery.

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

It was all original and unmolested when I got it with a 3 cell 6v and the manual calls for a 6v 4ah battery, additionally the bulbs in it were 6v bulbs...where are you seeing that it is a 12v system?

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

Yes, the manual calls for a 6v 4ah battery (which is what the dead original was)..the replacement is new and has overheated the wires since day 1 under my ownership (lighting has never worked on my watch) being new, the battery isn’t shorted. Also, a 6v battery shouldn’t be overheating wires on a 12v system (which this isn’t according to the bulbs, original battery and service manual)....i think it's gotta be a short but I’m stumped

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

Disconnect all bulbs and start checking for continuity through the positive lead with the battery unhooked. Start disconnecting wires until the short breaks, if there is one.

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

All the bulbs were already removed from the bike before posting with the exception of the speedometer odometer bulb that I can't remove (but I unplugged it). As mentioned, I disconnected all wires to the engine, the blinker relay, the CDI and the diode. I've also disconnected individually many other wires and as mentioned in my first post, the only one that seems to stop the problem is when I disconnect the black wire that comes through the frame at the 4 way connector by the handlebars but I suspect doing so is essentially disconnecting everything at once? The only place I see a black wire coming out on the rear end of the frame tube appears to be going to the blinker relay (round aluminum can). Again, I checked all the switches and buttons and components I could think of up front as well as isolating all the rear lighting too.....I just don't get what the heck could be causing this. I highly doubt there is a break inside the frame tube and all the wiring entering and exiting is well wrapped from the factory.

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

Well the black wire is battery power after the ignition switch and it runs throughout the bike to the brake switches and the turn signal relay/selector.

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

So I suppose if I don’t have the problem after disconnecting that back wire from it’s 4 way terminal that must tell me the issue is somewhere on the handlebars or front of the bike

Re: 1982 Honda Express NC50 wiring short (can't find it, please help)

Check for continuity to ground at the 4 way after unplugging the relay. If none then the relay or the black to the relay (also possibly the grey from it) are the issue.

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