Connect with us

Automotive wire size

Discussion in 'Electronic Repair' started by Chris Adams, May 30, 2004.

Scroll to continue with content
  1. Chris Adams

    Chris Adams Guest

    I have a '91 Toyota Corolla. I have recently replaced the wires on
    the licence plate lights (in the back). The original wires
    don't have any size markings, they could be either #18 or #20.
    I used #20 wire as replacement.
    My question is: if the original size is #18, is it ok to use
    #20 as its replacement? The lightbulbs are 12V mini lightbulb.

  2. maxfoo

    maxfoo Guest

    does the bulb draw more than 11 amps???

    Load Carrying Capacities (see table below)

    Remove "HeadFromButt", before replying by email.
  3. James Sweet

    James Sweet Guest

    That doesn't really apply to automotive, for an 11A load you'd want at least
    #14, but #12 would be better depending on the length of the run. At 12v the
    voltage drop over the wire becomes much more important.

    If the bulbs are bright enough then your #20 will be fine, I would guess
    they don't even draw an amp between them.
  4. Very correct, it doesn't. A lot of people -- including some of the
    beancounters at some of the automakers -- use tables like this to figure
    out "acceptable" wire sizes, with yucky results.
    They're 3, 4 or 5w items, so a max of 10w at 12v, so yeah, less than an
    amp max. That said, #20 is generally NOT used in automotive service for
    mechanical-weakness reasons. #18 is regarded as the minimum acceptable
    gauge, even where #20 would be electrically acceptable.

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day