Hey Kevin,
If it hasn't been mentioned already, a must-have is Dan Masters' book on TR6 electricals. You can get it direct from Dan himself. It is so good that a friend borrowed my copy and has yet to return it. Oh well. Back to wiring on the TR6. Many of us that run the 6 have found that, depending on the year, disconnecting some features of the circuit have benefits. For instance, in my 73 they had a system under the seat for seat belt warning, etc. which I disconnected (don't have OE seats). Also, I bypassed the rheostat on the dash for the lights. They are dull enough, why would I want to make them more dull! Also, I took out the circuit for the floorboard courtesy light (the switch in front of the shift) because this is a great way to kill the battery by inadvertently leaving it on. That is why a really good schematic is valuable, to see what you can do and what you shouldn't do. The book has a schematic for every year as a foldout. I even found a mistake in my new wiring harness which the marketer admitted with much chagrin after I pushed the issue on the phone. So much more the reason to trust but verify everything you do with wires.
Bill