To all that have installed a Painless wiring harness in a 67-72 - do you have any advice on modifications that were made during the install?
I did a search of the forums and found a few references to "tweaks" that were made during the troubleshooting phase such as diode added to the white alternator feed, headlight switch jumpers, radio only working din the ignition on position.
I am in the process of wiring my truck (70 GMC) and want to try to check all of these things while the wiring is still easily accessible.
Thanks in advance.
Kevin

My mods so far have been relatively simple, mainly pulling the Packard 56 connectors out of the fuse block to shorten up wires cleanly to eliminate as many pigtails and splices as possible. It's relatively easy, but I highly recommend a good set of crimpers and practice!! One major change I did was to pull out the tail light group (brake, turn, backup) and use the American Autowire rear harnesses to take advantage of the plug and play of the original design to really clean things up. It allows one less wire running to the back, and the only cutting I had to do was on the end where the wires plugged back into the fuse block.

Sorry, haven't had a lick of electricity run through my wires yet, so I can't say it's been problem free. But overall, the Painless kit is clean and comprehensive.

The bulkhead has several unused openings...that you can take advantage of to add your own wires to keep it looking as stock as possible, you need both female and male Packard 56 connectors. There is one big slot open as well, its a Packard 59 series (a bit harder to locate both male/female).

There is one big slot open as well, its a Packard 59 series (a bit harder to locate both male/female).

I have been trying to get Painless to confirm that the one terminal is a Packard 59. It is because that wire is 10 guage and (from what I have read) it is very hard to get a ten guage wire to fit into a Packard 56 terminal. A place that supposedly has Packard 59 connectors is www.terminalsupplyco.com but I haven't ordered from them yet. Plan to soon, since I have decided to redo that wire (#916) with a different routing.

terminal supply does sell the Parkard 56/59 series connectors in both male/female sides. I know because I have purchased them from them.
Just specify the correct p/n for the desired wire gauge and if you want brass or the tin plated type.