Weird light issue. Need help please

Help me with a lighting issue please. I have 6 of these strobes around my truck. This one pictured has some dead LEDs in it, so I decided to buy 6 new ones. When I took this one out and plugged in new one, it won’t come on. I went to a different location and same thing, no power to it. I took the light and connected to a battery to rule out it being dead and it came on. So I removed the circle marker light pictured and connected the new strobe and it comes on. I put the old strobes back up there, they come on. For sone reason, the spots where the current strobes are will not power new ones. Clearly power is up there since the current lights work. Any idea why this is happening?

 

Are you telling me to use the negative wire in the positive spot? I don’t believe I tried that. If that works, how am I to understand the reason the current LEDs are working?

 

I stuck a circuit tester in the live wire connector to verify positive and connected the corresponding wire to it from the light. I don’t believe I reversed it though.

 

Will do tomorrow and report back. Thank you!!