Complete Wiring Harness Overhaul

[Foswick]

You're making it too complicated. The image below is a portion of a wiring plan I am working on. It was easy to set up in Excel.

I get the appeal of centralized documentation, but I would argue that requiring an external spreadsheet for the information adds complexity, too, just in a different way.

I come from an engineering tradition that encourages documentation as close to where it matters as possible. External documentation is always suspect and rarely where you need it when you need it. I look at it like this: Is it better to keep a list of bottles I have on my shelf and what each contains? Or, is it better to put the "poison" sticker directly on the bottle? I favor labeling the bottle.

I consider that spreadsheet a good planning document. But, it requires you to have that document and trust that it is up-to-date. If circuits are physically labeled, the information is where it needs to be and is more reliable.

I just think about what I wish I knew when I was crawling around trying to figure out what's going on with existing wiring. I want to know:

• Where does this wire go?
• What is its capacity?
• What is its actual load?

Capacity won't change unless the wire changes length. So, I do myself a disservice by not labeling that wire directly. And, where the wire goes will change infrequently or never, and it is a high-value datum, so that should be on the wire. The only issue is that actual load can change without replacing the wire. I might, for example, replace an incandescent fixture with LED.

I have seen the 3x5 card approach, where each bus or panel has one of these cards. That approach seems to work pretty well. You can just look at the card and see what's there without having to try to read all of the tiny heat-shrink labels. And, it is easier to update if the actual load on a wire changes.

 

[jssailem]

I do myself a disservice by not labeling that wire directly.

I would agree. You also need to consider whether the label is visible when attached to a power block. I have been working on my project for several years. Upgrades have been fun. When working on a bench, I might have 6 wires with new labels, connections clamped and shrink-wrapped, only to discover that when the screw is tightened on the connector, the label is 2/3rd not visible. It is too close to the connector (can not read on an 18AWG wire), or has rolled towards and behind other wires.

 

[Foswick]

You also need to consider whether the label is visible when attached to a power block.

Yeah, fair point. That's what I don't love about heat-shrink labels - they're not easy to read.

 

[Stu Jackson]

I come from an engineering tradition that encourages documentation as close to where it matters as possible. External documentation is always suspect and rarely where you need it when you need it. I look at it like this: Is it better to keep a list of bottles I have on my shelf and what each contains? Or, is it better to put the "poison" sticker directly on the bottle? I favor labeling the bottle.

I agree. My background, too. Somewhere around the early 90s, some new-kid engineer draftsmen started to get lazy. They would do the drawing, but instead of labeling, in writing with an arrow, the description of what the part was, they stuck a number on it and then did a separate table with numbers and the description. Sometimes they even put this table on a completely different sheet! Regardless of where the table was, it meant only one really stupid thing: you had to now look in two places to figure out what you were seeing!!! It drove me crazy and I wasn't the only one. Some idiot tried to tell me "But, sir, it's all about 'draftsman efficiency' ," but I didn't buy that one. Probably because the guy who tried it didn't have tears in his eyes when he said "Sir."