Not today, but yesterday. Trailered my RD400 and Honda 350F up to Ohio to ride with my brother on his Offbrand CB350. For quite a while now my RD would not idle with the headlight on and not keep the battery charged and I simply figured it was time for brushes and a perhaps a new voltage regulator. While on the ride I let my nephew ride the RD so I could give it a good look over from the sides and rear. Soon, every time he would hit the brake the engine would sputter. Then the bike started not running at all with the headlight and tail light on. So I had him turn everything off and we headed back to the barn. But then when he would turn either blinker on the bike would die. So we had him go all electrics off and he made it back to my brother's house.
We suspected a bad ground so I popped the headlight off and started wiggling wires. Once in a while I could get the neutral and oil light to illuminate but it was very sporadic. I shook and cleaned every connection in the headlight bucket but could not keep the dash lights on steady. My brother started pinching the wire harness at the bucket and worked his way back. Down under the tank, about even with the spark plug he was able to start making the dash lights come on steady. He took an X-acto knife and cut the sheathing around the wire harness and there he found the red power supply wire with a tiny bit of old electric tape on it. He carefully pulled the tape off and there the wire was corroded in two. The sheath had a lot of water in it that had been in there for a while as it was all rusty colored. The red wire had not been spliced but just a nick in the insulation. It appears that at some point during the production line the wire was nicked and taped over. After all these years it finally corroded through and the wire burned in two pieces.
My brother carefully stripped the wire as there wasn't enough slack to waste any, and put a water proof butt splice on, then heat shrinked that, then with self sealing vinyl tape did a very professional job of sealing the wire harness back up. As an added bonus, he took some wire he had and stripped the insulation off that and put it in the harness sheath as a drain in case water ever got in there again. During the long ride that followed, I had full use of the headlight and tail light, all blinkers worked as advertised and my brother said the headlight was brighter than he'd ever seen it. As a bonus, when we returned, the battery was fully charged and showing 13 volts after I shut it off. It runs crisper, starts much better and it will beat the dickens out of those 2 off brand CB350s 8-)
We suspected a bad ground so I popped the headlight off and started wiggling wires. Once in a while I could get the neutral and oil light to illuminate but it was very sporadic. I shook and cleaned every connection in the headlight bucket but could not keep the dash lights on steady. My brother started pinching the wire harness at the bucket and worked his way back. Down under the tank, about even with the spark plug he was able to start making the dash lights come on steady. He took an X-acto knife and cut the sheathing around the wire harness and there he found the red power supply wire with a tiny bit of old electric tape on it. He carefully pulled the tape off and there the wire was corroded in two. The sheath had a lot of water in it that had been in there for a while as it was all rusty colored. The red wire had not been spliced but just a nick in the insulation. It appears that at some point during the production line the wire was nicked and taped over. After all these years it finally corroded through and the wire burned in two pieces.
My brother carefully stripped the wire as there wasn't enough slack to waste any, and put a water proof butt splice on, then heat shrinked that, then with self sealing vinyl tape did a very professional job of sealing the wire harness back up. As an added bonus, he took some wire he had and stripped the insulation off that and put it in the harness sheath as a drain in case water ever got in there again. During the long ride that followed, I had full use of the headlight and tail light, all blinkers worked as advertised and my brother said the headlight was brighter than he'd ever seen it. As a bonus, when we returned, the battery was fully charged and showing 13 volts after I shut it off. It runs crisper, starts much better and it will beat the dickens out of those 2 off brand CB350s 8-)