48v charging/wiring question

[1970buick]

Yes,#4 was with charger plugged in


Without charger plugged in the receptacle +/- reads 36.8v

[Sergio]

On Your first photo where the red positive wire for your lights goes around the battery, it appears that there is a black wire down there that is cut with exposed copper... kind of hard to tell from the picture.

You may have a bad OBC, You can run the negative from the back of the receptacle directly to pack negative just to get a charge on the batteries, but You will need to unplug the charger manually once you get close to 60v.

[1970buick]

Sergio, no cut wires or exposed copper. Bad pic

I spliced the negative wire from receptacle and ran it straight to negative of pack. Charging now. Does this positively identify bad obc?

[Sergio]

There should not be that much drop in voltage as You measured from the charger receptacle.

That is usually an indication the SCR inside the OBC that controls the current is damaged and not allowing current to pass from the charger through to the batteries.

[1970buick]

Originally Posted by Sergio

There should not be that much drop in voltage as You measured from the charger receptacle.

That is usually an indication the SCR inside the OBC that controls the current is damaged and not allowing current to pass from the charger through to the batteries.

So, this means replace the obc correct? I did do the bypass already with no luck. Any other possibilities?

[Sergio]

You can double check the negative connection from the receptacle to OBC is good.
Also check the connection from OBC to B- and the Pack negative cable from B- through the OBC to the battery.

If it is all good, I would say the OBC is bad.