Rallye Dash Harness Question

[challenger_73]

Hello all,
I need a little assistance with my dash harness. I just cleaned & re-taped my entire dash harness. At the end of the harness where the electrical block goes through the firewall I have a black & gray wire that is hanging loosely. I followed the wire back through the harness and found that it connects to the tachometer. I called Bill Evans at Evans Wiring today & he told me that on the 73 & 74 Challengers,  that wire did not go to the electrical block. He said that it was a separate wire that went though the firewall using a rubber grommet & connected to the negative side of the Coil. Is this correct? If so does anyone have a picture of where this wire is supposed to go through the firewall & how it is routed to the coil? I have attached a picture of the wire. Any help would be appreciated. Thanks
challenger_73

[Grec]

That IS correct. I don't have a pic, but I believe the hole is right around the bottom left of the brake booster. Gray wire, black stripe.

[challenger_73]

Thanks Grec! Apprecdiated.
challenger_73

[venture]

Now on mine the gray wire with black tracer is hardwired to bulkhead connector and comes out on cavity #4 , which the shop manuel says,and is wired to circut with fuel gauge,etc using fuse #6. The #4 cavity on the bulkhead is the bottom one closest to the drivers side  valve cover on the very bottom.Could  not find anything in my harness that would have been a seperate wire that color that went no where.