It doesn’t show the wire from the panel to the body, grounding the whole thing. Assuming there is one on the S2, as on the 3.8.
Jerry
Hi Jerry,
Thanks, good catch! Yes, on the S2 there is a grounding wire per your earlier post. Connects to the screw post that holds the x2 double female bullet connectors.
B.
All,
I wasn’t aware there was a ground from the body to the panel. I admit though, I was mostly concerned with the colored wires and never worried I wouldn’t know what to do with the black grounds. 
I can edit my drawing and add the panel ground. Can someone tell me where does it ground to the body? Was there a ground lug on the firewall that it comes from for example?
If my car (Series 1.5) was in my possession and if the dash was still opened up I would be happy to confirm this for you but in any case it’s my understanding that the ground lugs for the dash sit behind the tach on the bulkhead as shown here:
The black wires that connected to the double spade are disconnected in this picture and hanging below. Of course, ISTBC!
John,
On the S2, new wire harness from SNG, main ground wire (black) for the center dash panel feeds from the left wire harness and ties into a larger black wire on the left side (female spade) and lands around the steering column area. This large black wire runs to the right side, also a female spade and lands around the passenger side glove box area.
At this point, I am not sure how this grounds to the body… more to come.
Thanks,
Bob
Hi John,
One additional comment… On the later S2 that I am reassembling, #2 on the Washer Switch is connected to a Light Green/Black wire, not a Green wire. This may be something to check on and maybe update your diagram.
John, your diagram, and the Richard Liggitt diagram match up well (documentation matches). These diagram have been most helpful and will continue to be.
Thanks again,
Bob
Thanks John!
That was quick! I know others will also greatly appreciate your diagram.
Regards, Bob