Tail Lights

[Tikvah]

I'm installing new tail lights and noticed something a bit odd with the wiring.

With the tester on the wire, on reverse, I get power to the reverse ground wire when in neutral.  When I shift to reverse, then the power switches from the ground wire to the positive wire.

The new lights simply have one common ground for all the lights... this switching of the ground from + to - isn't going to set well with the new lights.

[Jim Eh.]

LEDs I take it? That would pose a problem. What about wiring in an alternate ground and capping the original ground wire? You should have + on your positive wire only when it is reverse and  a ground connected all the time.

[TedCalvert]

use a relay.