It sounds like you tested from speaker positive to speaker negative though, instead of speaker positive to chassis ground. Disconnect your battery negative cable. Test from each speaker positive on the harness to a nearby chassis ground. You should not get any continuity whatsoever. Then, while you're at it, test continuity from all your speaker negatives to the chassis ground, you should get a very low ohm rating.
Yes, I tested the positive to positive speaker wire and negative to negative speaker wire to make sure they were all connected.
So I should test positive to positive speaker wire and negative to the chassis ground to get no continuity?
And then test negative to negative speaker wire and positive to the chassis ground for a low ohm rating?