Usually there is only one for both headlights and this is by the fusebox.
That same ground is shared with the alternator, control box, wipers, and a
whole host of other things on a 67 so the ground itself is unlikely to be
the problem as that would cause all sorts of funny interactions between
circuits, and seeing how it does everything it could well be behind the
dash. If both sides on both beams are affected, and the main beam tell-tale
glows brightly when the headlamps don't, then it is probably the 4-way
bullet connector by the right-hand headlight. If the tell-tale doesn't glow
at full brilliance either then it is probably the dip-switch. Of course a
short-circuit somewhere can cause melted connectors as well as dim or
extinguished bulbs. Normally this would smoke the wiring, but if you have a
'weak link' elsewhere in the circuit like an iffy connector or dodgy switch
this is more likely to fail which saves the wiring. Easiest thing to do is
power them up then track the voltage through the main lighting switch,
dip-switch, coloured connectors by the right and left headlamps (all
bullets, not just one), black connectors (ditto) by the left and right
headlamps. You should see 12v on the coloured wires and 0v on the black.
----- Original Message -----
> Pretty sure it's a ground somewhere. Did notice that the passenger
> headlight plastic three prong connector where the bulb plugs into was
> melted! Driver's side connector ok. I am running Hella Halogen H4's. I
> have a 96 amp alt. installed.
> Checked the 3-wire ground connector above the oil cooler under the front
> cross brace. Seemed ok. Where are the other ground connections for the
> headlight circuit?