A quick note for Slab-side owners especially, and owners of older stuff too: upgrade the wire from the battery to your starter relay! Mopar alternators of the mid 1960s varied from about 30 to 60 amps capacity maximum, so the #10 AWG wire dedicated to running the dash stuff seemed adequate for the time. It wasn't and isn't. I run a 60A alternator now. Most of the wiring is original. What isn't has been upgraded for larger ampacity when useful, like the headlights, or upgraded to #14 gauge on the principle that I never replace any old, defective wire with anything smaller than 14 AWG in my car for the ease and availability of supply. MOST of the old stuff is still there. I run 12 gauge for 20A circuits, 10 for high demand, and NOW have upgraded the old 10 AWG wire from the battery to the 3/8" stud on the starter relay with #8 AWG. This has been MOST satisfactory! I've gained an additional .6V in steady voltage available when running the pusher fan, which previously would pull system voltage down to ~11.5 VDC from the curb idle voltage of ~12.5 VDC. Now, I have about 12.1 VDC for the dash circuits at curb idle while running the pusher. This was exactly what I expected by increasing the ampacity/conductance of that wire. I still use 6" of #12 AWG fusible link at the battery to protect this crucial conductor, which now is CORRECT for #8 AWG, being 2 standard sizes smaller. I've had #8 from the alternator for 4 yrs, ever since the fire resulting from the busted motor mount which shorted the old alternator stud to the fender, but had left the old stuff in until now working on the "If it ain't broke..." slothful principle. BUT, as results show, it WAS "broke" insofar as significant voltage drop resulting from inadequate conductance can be said to be a defect. I can live with the ~ .3 VDC drop I now have far better. Try this yourselves if you have time. I got a nice, tinned copper ring terminal meant for #8 AWG wire, crimped and soldered it to the wire, and ran the battery end into a split bolt joining it to the fusible link from the battery. It takes less than 30 minutes, and you'll have more power for your dash components for the trouble.