Extra brown wire at tail bundle - 1982 Honda NU50

Under the gas tank where brake/tail/rear signal lights connect, I have an extra brown wire which has been covered in what appears to be heat shrink. I am chasing some lighting gremlins and wondering if there is a "connection" (pun intended) between this extra wire and the other issues I'm having.

I know that on the NU50M there is an extra pink wire which connects to resistor on license plate holder, but no such extra wiring on the NU50 according to the diagrams.



Re: Extra brown wire at tail bundle - 1982 Honda NU50

Captain Janeway /

Re: Extra brown wire at tail bundle - 1982 Honda NU50

Thanks. I actually have the manual. That's how I know it's an extra wire. Doesn't show in the NU50 or NU50M diagrams. Hence my question.

Re: Extra brown wire at tail bundle - 1982 Honda NU50

Captain Janeway /

It's not extra. There should be a brown wire going up into the rest of the harness. Looks like. It ends up in the speedometer.

What's the actual problem you're trying to troubleshoot?

Re: Extra brown wire at tail bundle - 1982 Honda NU50

Well, I haven't had a chance to check out everything, but:

Oil level indicator light does not go out (even when I manually raise the sensor).

Turn signals don't seem to want to work very well.

Rear light is out now - no running or brake/stop light.

Oil indicator was not coming on at first so I checked sensor resistance per manual (pg 13-17). It read bad so swapped in a different sensor (which read resistance at both down and up positions, although not as much as manual says in up position. Manual mentions to operate the turn signals and also says to check for loose connections, so I figure that may be causing my issues - just haven't had a chance to go through connections all around the bike yet nor check to see if brake/stop light is blown.

A funny thing about this bike - as I said it is labeled as an NU50 and cam with a smaller battery and case, but the terminal ends had the rectangular connector like on the NU50M, but unlike the NU50M it doesn't have the extra pink wire in the tail bundle for the resistor (pg 16-2) - instead it has that extra brown wire which I mentioned earlier.

So, I'm confused, but will carry on trying to figure this out. One more thing - I confess to really not knowing my way around a multi-meter too well - just kind of learning.

Thanks in advance for any suggestions.


Re: Extra brown wire at tail bundle - 1982 Honda NU50

Oh, one more funky thing. There are two green and two red wires terminating at the battery (like diagram for NU50M on page 16-2), vs. just one each for the NU50 (page 16-1).

It's almost like someone put a NU50M wiring harness on this NU50.

And the strangeness continues.


Re: Extra brown wire at tail bundle - 1982 Honda NU50


Due to blizzard conditions here in North Iowa (expecting 4-8"), had time to spend in the "ped shed".

Tail/stop light was blown - new 1157 bulb solved that problem. Closer inspection of wiring reveals that not only is it an NU50M wiring loom, but someone has messed with it as well (yellow/red stripe starter wire has been cut and a black wire spliced in) since no starter, no problem.

Swapped in a different turn signal relay and that seemed to fix my weak turn signal issue.

Still a problem with the Oil sensor. Light doesn't go out, so for now swapped back to the old sensor until I can do further testing with one I know works (I have 3 working bikes now, plus a parts bike and some additional spare parts.

Have drained fuel lines and carb, took out battery and stabilized gas in tank. It will sit until Spring now.

On to the next project - a pretty little yellow 1978 Express.

I'm sure that I'll be back with more questions.


« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account