Reverse lights only work with parking/headlights on

Ok the problem deepens. Replaced #14 fuse engine compartment. And reverse lights work normally. But marker/parking lights won't turn off once turned on!
Marker lights turn off when #14 fuse is pulled. Or "D" relay is removed. They can then be reinserted and the marker lights will remain off untill turned on from inside cab.
I swiched "C" & "D" relays. Same results.