I'm having an issue with my wiring. I'm in the process of putting my car back together and i'm testing the wiring. It's a 67 with the original harness that is in great condition. Anyway, here's my questions...

1. On the column harness, i'm getting juice at from the horn wire going into the column, is this normal?
2. When my key is on and I put the left turn signal on, the right arrow lights up on the dash and my heater control light comes on.
3. When my key is on and I put the right turn signal on, the left arrow lights on the dash and my heater control light comes on.
4. The turn feed and the Hazard feed going up the column don't seem to have a full 12v (my test light don't light up very bright when I test these 2 wires).

There seems to be some back feed through the fuse panel when I do 2 and 3 above.

I bought a used column on ebay and it looks to have a new signal switch in it.

1. Normal. Pushing on the horn button grounds the circuit causing the horn to sound.

2 & 3. Bad instrument cluster ground. The cluster is ground via the center screw on the plastic bezel face surrounding the instrument pods. That ground is notorious because a loose screw, or rust behind there can made the ground ineffective. Also, the thin ground strap to that screw location from the back of the instrument cluster can be bent or broken off easily by a previous owner. Many of us have run a second wire from a ground at the back of the instrument cluster as a backup.

4. Don't know. There is a separate relay for both systems. But the bad ground could also be affecting them.

I was thinking I could be a little bit more helpful.

For the grounding issue - remove the two plastic bezels under the steering column, remove the 3 bolts in the steering column support bracket under the dash and drop the steering column down and let it hang. Remove the 5 black Phillips screws in the plastic instrument bezel and gently work it back from the dash. With an inch or two of clearance at the top, you should see a thin steel wire with a loop on the end that goes over the metal tab the center bezel screw threads into. Make sure that loop and wire is present, clean up the threads on the screw and metal tab, and put it back together making absolutely sure the center screw goes through the metal loop and into the dashboard tab.

If that does not work or the metal loop/wire is missing or out of place, you will have to disconnect the speedo cable and the wiring harness connector into the instrument cluster from below/behind and pull the cluster.