No Low Beams On 66

I had the same issues that you have had on my painless harness. No wiper motor and no low beams. Turned out my harness was miswired at the connectors by Painless. Two wires at the dimmer were crossed and the same for the wiper harness but the miswire on the wiper was done at the wiper switch - They listed a drawing of the back of the wiper switch which showed color-coded wires and which blade went where and also a listing which showed which spot (a,b,c,d etc) they went on the back of the switch. The drawing was wrong but the list was right (I initially followed the drawing.) since then they have corrected the diagram and you can download a new one on their site.
In addition to that I had a miswired connection on the blinker harness. It must have been Friday on a holiday week-end when they wired our harnesses up?
Of course there is no mention on their website about previous diagrams being wrong.
Your High and Low beams use the same ground so if one works then the other should so I'll bet its crossed/miswired connection.

Also, I believe I got two books with my kit but one was for 65 - 66 and the other 67 - 68? At one point I grabbed the wrong book and it goofed me up a bit. Check the front cover and make sure you have the right one, they look the same.
Or even better, Here's a pdf of the latest diagram. See pager 24 for the wiper switch diagram.