I didn't want to derail
@S4Cruiser 's build thread so I am continuing a discussion in my own personal build thread.
@Roastchestnuts here is what I did for the updated Toyota headlight harness install in my early 40 series.
I did two main modifications to the harness. 1. I cut off the bulb power tap that the new harness uses to trigger the light relays. I have the new harness get it's activation power via the stock fender block. Not an original bulb connector.. since that got its power from the block anyways. Cleans it up a lot. Hopefully the pic below is clear:
View attachment 3321021
I de-pinned the h4 bulb connectors and threaded the wires through the stock buckets, then re-pinned the connectors. I installed a new grommet as well to protect the wires:
View attachment 3321014
Second is I trimmed a lot of excess wire out of the harness that led to the bulbs. Since its a universal harness it comes with A LOT of extra wire. On the driver's side I cut out 4'! I also trimmed wire from the fuse wires as well. I don't like stuffing tons of unnecessary wire away. Worth it to me to take the time and trim and have it clean. I have my fuses and relays mounted on a custom bracket next to the battery. (The bracket is painted now. This was a mockup photo). I don't like drilling holes and using factory bolt locations is always nice.
View attachment 3321015
Hopefully that is helpful and clear as mud