Translation of this page is incomplete.
Collection of all electrical (plus and minus) connections (in work). Click on pictures to enlarge.
Corresponding threads in dmctalk.org:
DeLorean Ground Schematic

Ground Location List

Other Links:
Voltage Drop Testing


Overview
Front
At the mounting point of each radiator support brace. On page 1-3-1 of the parts manual the brace is parts ID #1. The bolt where it attaches to the frame provides grounds for much of the front of the car (lights, horns, etc.). It helps to remove the cover to the brake fluid reservoir, then it is easy to access from there. There are ground points on both of the braces.There are multiple mass connections behind the Frontlight.
Inside
Right side of the Radio / A/C Metal Bracket (dash). Center Console to be unmounted.
Passenger side behind the parcel board. The parcel shelf wall to be unmounted.
Drivers side, under the parcel shelf with the ECU mountings & harnesses.
Engine
Auf der Fahrerseite geht ein Massekabel zu einer der Schrauben, die den Zündwiderstand an seine Metallhalterung befestigt.Ein Massekabel geht auf die Schraube, die den 'Vacuum advance solenoid' an den Gemischregler befestigt.
There is a important connection between frame and E-Box right under the jump start log.
Passengers side, connection between engine and engine mount.
Passengers side, on the forward side of the intake manifold, with a red heat shrink & blade connector. This one comes from a harness & if unplugged causes the Lambda system to not operate correctly.
There's a connector with about 9 terminals, one is ground, that's parked inside the washer bottle cover. But it's not technically a "ground point". But it does ground much of the dashboard area! The black cover with the bottle inside it that's held on with way too many rusty screws. You can usually pull the cable out and get to the plug without taking the cover off. Carefully pull out the grommet that's right next to the cover.
Rear
On passengers side, the battery mass cable reaches a frame connection near the trailing arm (not the trailing arm bolt itself). There is a counter (lock) nut on the back side.There are frame connections behind of each rear light (only for anti static reason, can be ignored)