Hayk

iTrader: (1)

I need stranded primary copper wire for an electrical repair in my engine bay. Specifically the wires on the engine harness for the Air/Fuel sensor plug.

They need to be the same size and color so I was trying to figure out their size by matching up a sample of wires I had from an old O2 sensor. Unfortunately after multiple google searches and visits to local stores, I realized it’s not easy to find wires in this small of a size.

After a lot of time spent on this, I’m 90% certain the wires are 20AWG but don’t want to make a mistake placing an online order.

Here is some clues:

1. The terminal and weatherproofing seal kit I bought is sized for 20-22AWG.

2. They’re a little smaller than 18AWG after comparing them side by side.

3. I measured the diameter of one stand, counted the number of strands, and measured the overall wire diameter. After referencing an online chart, I found that it may be 20AWG.

d = 0.18mm or 0.007in of one strand
n = 19 strands
D = 1.55mm or 0.062in of one wire with insulation

d^2 = 0.0324in^2

CMA (Circular Mils) = d^2 * n = 0.0324in^2 * 19 = 0.6156

Here is the references I used including some photos.

https://www.calmont.com/wp-content/uploads/calmont-eng-wire-gauge.pdf

LeX2K

Do you have access to a local help yourself junk yard? It is so much easier and better to use OEM wire I keep bundles of it on hand for such repairs. Bonus is you get real copper wire most now is aluminum with a copper coating. If not, 20-22 gauge is common for low current stuff I'd say most of the car wiring uses it.

Hayk

iTrader: (1)

That’s a really good idea! I’m gonna see if I can source some OE wires from a local salvage yard. I’m not sure if it’s ‘help yourself’, but hopefully they can help.

LeX2K

I randomly pull wire could be a trunk harness or whatever is easiest to access. Can patch/fix most any wiring issue like broken door harness etc. or I use OE wire for any project that needs wire. Up to about 2001 Toyota is best after that the insulation starts to get less durable.

Here's my wire fix box.



If you can't pull yourself then buy a trunk or door harness something like that. Body harness has good variety of gauges, for example the wire run that goes from the left hand side fuse box along the rocker and to the trunk.

OGYOTA

20ga seems about right.

I recommend TXL wire if you want to go with new wire. I usually buy it in small quantities from ebay sellers.

Here is the link of what I bought last time I ordered some. Not surprising the price has increased, my last purchase was Nov 2021 @ $27 for all these colors. Now its at $39
https://www.ebay.com/itm/28175034761...UAAOSwHnFVk~lc

Typical "primary" wire from the parts stores is absolute garbage. TXL wire is pretty standard for most domestic car manufactures to use for engine harnesses. Next option would be MIL Spec wire like Tefzel.