Topic: 75 CB550. Riding at night and lost headlights brake lights and rear running ligh

[scottly]

The most common cause of a melted ground wire is when a battery has been connected backwards, with a large current flowing through the rectifier. Since the rectifier is connected to the battery directly, if damaged it can drain the battery even when the key is off. See if the wires have any evidence of overheating.
Make sure the battery is disconnected before you try to charge it, and most tenders are not proper chargers. Even some "smart" chargers won't start to charge if the battery voltage is too low.

[scottly]

BTW, the rectifier doesn't have two black wires!?? Yours look to be charred black? One used to be red and the other used to be green. It did pass the test, but I would take a good look at the harness it plugs into for melted insulation.

[turin39789]

The most common cause of a melted ground wire is when a battery has been connected backwards, with a large current flowing through the rectifier. Since the rectifier is connected to the battery directly, if damaged it can drain the battery even when the key is off. See if the wires have any evidence of overheating.
Make sure the battery is disconnected before you try to charge it, and most tenders are not proper chargers. Even some "smart" chargers won't start to charge if the battery voltage is too low.

I used the jump pack to bring some life to the battery and now the tender is charging it up.

I'm assuming new harness is the only solution and shouldn't try patching that ground cable.

[turin39789]

BTW, the rectifier doesn't have two black wires!?? Yours look to be charred black? One used to be red and the other used to be green. It did pass the test, but I would take a good look at the harness it plugs into for melted insulation.

I'll take another look tomorrow, but where the rectifier connects looked fine and When I looked before I thought it was just electrical tape on those wires.

But if there is concern is it worth replacing the rectifier?  CMSNL looks to have a pricey one that looks OEM, or I know the combo unit brings out opinions.

[scottly]

The electrical tape might have been there to replace the insulation that had melted off??

[turin39789]

The electrical tape might have been there to replace the insulation that had melted off??

Melted off or someone patched with bare stranded wire from the looks of it. I'm assuming my play is to patch the ground or replace the harness and get a rectifier/regulator combo unit.

Also it  looks like battery might have been toasted.  Made time to check it and it was sitting around 3volts.  I disconnected it from the bike but tender  has no interest in charging it. Jump pack will take it up to 10v, but meter shows it just constantly draining.

[Deltarider]

It's dead.