Electrical nightmare, 1968 cluster lights, parking lights, horn, etc.

Should concider converting your ammeter to volts. Theres a few threads on here for this including pn# for the aftermarket sun volt gage needed to do this. I converted mine. You have to grind out a spot in the cluster housing so the needle gets full swing, and you reuse your original ammeter face. I also reused my ammeter needle too. I clipped the plastic needle off leaving a small space to glue the ammeter needle in place so it looks original.

You ream out the hole in the gage cluster housing for the + stud on the volt gage, insulate the + stud hole with a plastic grommet and plastic washers. The negative stud you ground right to the gage cluster housing with steel washers b and a nut. Then run a short wire from the 12v + stud off the volt gage to the 12v gage cluster feed stud off the back of the fuel gage.