EP500 Pro connecting to B230

I have recently added a B230 and watched the video for connecting them using the P090D To MC4 from the B230 and the MC4 to Aviation into the EP500 PRO.
The issue is the MC4 to Aviation cable that I have appears to be mislabeled. In the video it wants the PV cables from the P090D into The DC1 + and -. However on the on the aviation cable they do not say which negative cable is DC1 and Which is DC2 and as there are 2 of each there is no way to know which is which. Additionally the Cables with the DC1 - have a connector that is marked with a +. Now I am not sure if that is indicating what it should be plugged into but it seems to me that they should match. This is the same for all 4 of the input lines. Both - have the positive connector and both + have the Neg connectors. I have tried every configuration of the cables but none will provide power back to the EP500 PRO

Any assistance would be appreciated. I have tried emailing and calling and am not getting a response.

Hi @shirschhorn , Open charging mode requires a long press on the B230 key until it flashes. As for the PV line without wire label, you can refer to the following diagram to wiring
lQLPJwBVVxguQuDM0s0CJ7DLLAxkP9VT7wOW2iwywEkA_551_210

Can I get some help to? I connected the b300 on the ep500pro but it does not charge. De light flash on the b300 and volt dc input start at about 50v but then dorp to 9v . But watt input is zero…0 …
I also cannot get the dc working on the b300 in stand alone with charge mode is off.

@bluetti_jimliendenicloudcom
Was it normal when using the B300 in charging mode before? Can your B300 currently charge and discharge normally when used alone?