LED's?

If the originals work the LED's should unless their defective.

I just thought of one more thing. Were you performing the test with the engine running or shut off? Reason I ask is LED's won't light up at all if the voltage is under a certain amount unlike a regular bulb that'll light up dimly even if the voltage is way low. The wiring going back to the trunk is alot longer and has a little more voltage drop so if your doing the testing with the engine off it's possible the battery voltage is just low enough and combined with the long run of wiring to the back causing not enough voltage to get to the rear's to light them up. Just a thought.