I am just wondering if there is a common problem area to look at or do I just start looking for a short in the wiring.

I think the back up lights are on the same fuse. If the turn signal wire shorts to ground it won't blow the fuse, it only makes that side blink really fast. The back up light wires are light green, and if they short to ground it will blow the fuse.

Great response. I don't have the 74 schematic with me either but think the heater connector may also be on that line. There is one in the Haynes Chevelle Manual avaible at Pep Boys or other places.
Try unplugging the back-up light connector on the column and (maybe) the heater connector and see what happens.

Thanks Guys, I will give your suggestions a try.

I found the trouble, it was a wire exposed for the electric fans which i had run to the terminal at the fuse block next to the turn signals. It must have hit the header it won't again. Thanks for your input.

Heard this stuff is a good insulation material.
http://www.racerpartswholesale.com/aero6.htm