There are quite a few orange wires under the dash to run different things,most of them run to the same fuse,the 20 amp clk-cig
I'll post a diagram that should help,but I always suspect any aftermarket install to be at fault
When put a fuse in that plug,you're back feeding the chime module circuit and the parking/marker light circuit. The orange wire is on the same circuit as the map lights
That plug goes on the back of the factory radio,the brown wire is to signal that the lights are on,so the VFD display will dim...
First plug orange radio memory
brown dimmer signal
Second plug,not hooked up on my car
Third plug is factory taped to two other plugs that look similar,have never been hooked up,must be something to do with a factory alarm or twilight sentinel.I don't have either.
This thread deals with the same situation, http://www.turbobuick.com/forums/threads/87-buick-park-avenue-digital-dash-installed.58151/
He used a dual output GM VSS buffer
Yellow VSS 4-out Buffer box from a Grand Am or Firebird Pre-1990
Here's one persons solution to the same problem. http://www.turbobuick.com/forums/threads/late-model-lesabre-gauges-in-a-turbo-regal.328909/#post-2591541
One of the 1157 bulbs in the taillights is in wrong.They are only supposed to fit in one way,but they can be forced in the wrong way.
It ends up shorting the brake/turn filament to the marker/running light filament.