Starter Disabled due to P/N

[murf]

Here is a picture of what looks like a diode on the grn/white wire.
The side where the alligator clip is the side that goes somewhere. The other side, a solid grn wire, goes to the plug.

No 12v on the grn/wht. Key on I get continuity from the grn/wht to ground with the neg clip on the grn/wht and the pos wire on the multimeter to ground. No continuity with with mulitmeter wires reversed. There is no continuity on the grn side of the diod.

I don't understand how 12v could be on the grn/wht when there is a diode in the line that would stop the 12v from getting to the plug. Do I misunderstand the diode symbol?