It is almost certainly the + is on the right hand side.
the DMM should read ~8 ohms from the left or middle to the right side.
If one of those left or middle shows 0 ohms to something like each other, or any metal, then those would be a ground..
or maybe it is possible that they are some servo type of signal?
You basically have 3 combos on each row. From left to right you have bananas A, B, C. And from top down you have rows 1, 2 and 3. fill out the table with ohms.:
- A1/B1
- A1/C1
- B1/C1
- A1/A2
- B1/B2
- C1/C2
we should be able work out the rest from there.