Orientation of auxiliary battery in VW Winnebago?

[vw_dude]

I removed the battery to charge it, then when was about to put it back i realized none of the wires is marked red for positive. There is shorter one, green closer to the front, and the longer, black, closer to the rear of the vehicle. I assume green is for negative/ground, the longer, black is positive. I checked the Winnebago instruction, there is info regarding battery location, nothing about plus/minus orientation. I thought red is an international standard for plus, apparently not for Winnebago.

[e&m_ghia]

Winnebago did grounds in green, but don't remember about this one. I put some red tape around the cable for our hot connection to the coach battery, to keep it memorable.

But to save yourself from the hacks of previous owners... Don't trust color codes. Check which one is grounded with a multi-meter.

I think our ground cable is also bolted to the chassis pretty close to the coach battery box, which should be easy to check. And the hot side should be energized when the engine is running, if the relay is working.

[vw_dude]

Not following basic color coding is very disappointing from technical point of view. Dont think would go US made camper route again.