Wire life

R

Richard

Member
Some wire questions in general:

1. On any of the engine compartment wireing, if the application states a certain gauge (ex. 14 ga.), and you go with a higher gauge wire (ex. 12 ga.), how does that affect resistance? I would think that the resistance would be lower, and hence more effecient?

2. Over time, wires get hot and cold, hot and cold, etc. Does this contribute to wire resistance? I would think it would. Some of my engine compartment wire feel real "hard" when trying to flex them, while a new piece of wire the same gauge feels very bendable.

3. In reading some of the threads in the wire section, there is attention paid to the "connection" points realtive to corrosion and resistance. I am guessing that this is also true with old wire thats been working for 30+ years. People who have been "rewiring" their engine compartment seem to state that their electricals work better, stronger, brighter, etc.

Any thoughts?
 
1. Imo, there is no reason to run a larger gauge wire than is needed to safely "run" a given circuit. If 14 gauge is perfectly adequate and 12 gauge is "better": then 10 gauge must be even better...

2. New wire in an engine compartment will soon become "hard", too. Though, maybe today's plastic insulation is better than the plastic insulation of 30 - 40 years ago. The important thing (to me) is that the insulation is not cracked or worn - exposing bare wire to the elements / metal.

3. Yes, I would think that all the connections have been cleaned or replaced and all the grounds have been cleaned...
 
Wire life is pretty much determined by the insulation, provided it was properly sized. Even then if it was undersized and conducted power at elevated temperatures, it is the insulation's deterioration that limits the conductor's service life. Environmental factors play huge Role as well; heat, chemicals, moisture, oils and fuels, uv; (just about everything in an engine bay), are hard on insulation. In the day, house wiring would out live by decades the wiring in a livestock barn.

Upping conductor size to reduce resistance is doable to an extent; beyond that cost and convenience(try rewiring your dash in 12 or 10 ga) are the main limits. The only reason to size up would be larger loads or longer distances. At least one trade size larger for big loads like lighting, trailering, auxiliary equipment, would be an improvement. Current, resistance and gauge size is all relative. Wire gauge is selected more along the line of current carrying vs temperature rise; and how that relates to adjacent conductors in a loom or conduit, not so much cost though I don't get putting toaster wire (the primary ignition feed resistance wire) in the engine bay loom. IH was one of many who bought that.

Connectors are the nemesis of any system. Clean and tight is the rule, weatherproof them as best you can. If they are corroded or show heat signs; get them serviced or replaced immediately. That is a failure mode that only escalates until you have a melt down or a fire.

If the insulation is cracking and flaking off, it's time to look at replacement.
 
I have a machine with round guides system, after more than 8000 hours I have made different tests with them, the main is a cut of a round of 30mm diameter, the idea is to check circularity and surface finish quality, I was thinking about 3000 hours was the limit of the life of them, but what was my surprise when after checked the tests they where pretty ok!, I normally use taper cut up from 15º! And my guides still continue ok.
 
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