I bet 5% looks pretty good, do you have any pictures of the new tint? Dark windows make a nice compliment to the Insight.
Here is how I did my grounds for those interested:
^Power steering rack to firewall ground. Drivers side of engine bay. The yellow pen is there to make it easy to see. Mine was within 0.5" of the length of the air box ground (a close duplicate).
^Tools/Materials required. The heat shrink and techflex are not required and probably of no benefit, just extra I had laying around. There is a shrink tube with a glue liner if you want to get real high class. 5x 6 gauge 1/4" ring terminals were ~$5 (they fit better on my 4 gauge wire than 4 gauge terminals did). I emulated the crimp tool with a (dull) chisel and hammer. You will need 2 total feet of wire for all 4 factory grounds. I recommend using an electrical corrosion/oxidation inhibitor on the crimps & mating surfaces of the terminals ("Noalox" from Home Depot/Lowes). *Not pictured: Hammer, heavy duty wire cutters (tin snips or bolt cutters etc.), 10mm socket/ratchet (preferred to have 12-18" of extension), you could probably get by with just a 10mm wrench; do what you can with what you have.
^A comparison of two different 4 gauge cables. The right cable came from Home Depot. I bent each ~9" length cables tip-to-tip and let them naturally unbend; these are the results. The Home Depot cable is much, much stiffer. Unlikely to be a problem, but for $4 I sourced the "#4 flex-a-prene welding cable"; most welding cable will be comparable. You will need 2 total feet of wire for all 4 factory grounds (I had ~3" leftover)
^Old vs. new cables. Pretty indifferent, aside from the failed repair made by a previous owner; I greatly prefer working with the brazed seam style connectors I used to the pictured blue plastic sleeved connector. If you can only source the latter I doubt it will be an issue.
Reflection:
-This is an easy repair. Give yourself time and you'll be fine, if you can change your oil or your air filter you'll be fine doing this. Don't over tighten if you're worried about stripped threads; ~drain plug tight or a bit more is fine, check them in a week for tightness.
Tips:
*Clean mating surfaces with 60 grit sandpaper. Use an electrical corrosion inhibitor (Search "Noalox", ~$2-3 at Home Depot & Lowes)
*The ground cables need to be long enough to flex back and forth with the movement of the engine (factory length is fine) so don't make them a straight line A to B, the curve is by design.
*Make an effort to source welding wire, or another flexible wire (usually have a high strand count). Home Depot wire would have made for more hassle, though it would have functioned.
*If you're feeling lazy, cheap, or scared, just give your old cables a good yank on the car before you remove them. If they seem solid and in good shape consider leaving them alone or just unbolting them and sanding the mating surfaces clean and reinstalling. Give your new crimps a solid tug before you shrink tube or install them. Give them a tug when they're on the car, make sure nothing is loose.
*The law of diminishing returns applies to the power steering-to-firewall ground. It's probably as hard to do as the other 3 combined (not that it's "hard", it's just in a hard to reach/see area). The outer diameter of the ring of the 4 gauge ring terminals I had was too large to bolt to the power steering rack. The 6 gauge dimension was fine. You could use the 4 gauge but would have to file away material from the outer diameter to make it fit. (The result would be a "D" shape ring terminal)
Difficulty level:
Easy. Low risk of causing a costly repair. Low risk of damage to car or parts involved. Low skill level, with no real negligible effects from a less than perfect repair. You can read about how many people (like myself) were driving with at least one severed ground cable with no noticeable effects.
Cost:
Majestic Honda lists OEM cables ~$8-9/ea.
Minimum cost is 2' cable ~$5. 5x ring terminals ~$5. I reused my negative battery terminal as it was in good shape. You can splurge and get fancy with the aforementioned extras if you'd like, I doubt your engine bay will care :]
Conclusion:
Probably an unnecessary repair which you won't see any noticeable benefit from. A nice way to kill a few hours if you're so inclined.
**Parts sources (Southern California local only):
IPS- Industrial Pipe and Steel, 91733. Wire, terminals, ton of other fun stuff.
Orvac Electronics, 91016. Shrink tube, techflex, about any other electrical supplies you could want. Sells its bulk wire and techflex ($0.50-$2/ft) in 10' or greater quantities only.
Both stores have great customer service and are very friendly.
(Google Maps is a great way to find local suppliers; try "welding supply" and "electrical supply" etc.)
Repaired + upgraded engine ground wires.
awesome!
