Brake Lights Come On With Side Markers -- Vice Versa

rodents?

 

A defective connection between the left or right rear combination light assembly and body ground points M1 or M2, respectively, could let the stop light circuit back feed the illumination and tail light circuit. I’d start by checking for continuity between body ground and terminal 1 (white wire with black stripe) on connectors M5 and M6 at the rear combination light assemblies. In the Electrical Wiring Diagram (more info), see the “Stop Light” and “Illumination, Taillight” pages of the System Circuit section.

 

Unplug it , and use a needle to "de-pin" the plug, [one wire at a time]

Then solder replacement wires to the indivedual damage wires , and slip some shrink sleeve over the joins.
then re-click the pins back into the plug.

If the wires aren't briken you could simply de-pin them and re-insulate with shrink sleeve.
Also liquid electrical tape is useful if you cant shrink sleeve repairs.


I've had good luck with our local "U-Pull" with some cutters , gettingplugs with pieces of wire and the correct pins for patching electrics.
Toyotas a reasonably "universal" with some of their pins, it is usually the plastic plugs [M & F] that change.

 

Where is that wire located? i wonder how that happened.

 

I also would wonder why it happened. If it looks like the insulation was chewed off, that's one thing. If it looks like it was melted off, then this wasn't the first problem back there, and the first was probably another short somewhere, maybe still needing to be found.

As for repairing it, the way to do it to Toyota's standards would be to look up that connector in the wiring diagram:

Toyota Service Information and Where To Find It | PriusChat

and get the part number of the repair terminals used in it. This post shows how that's done, and how what you find there also shows how the terminals are released from the connector housing (there's usually a primary and a secondary lock, and the primary is sometimes part of the terminal and sometimes part of the housing) and what crimp sleeves go with it.

You only need as many repair terminals (and as many sleeves) as wires that are damaged; the ones that aren't damaged can be left alone. Each repair terminal has a length of wire already attached, so you can cut back the original wire to a spot that's good, and crimp it to the repair wire at that point. Then you just click the new terminals into the right positions of the housing.

The reason auto/marine/aerospace industries use crimp connections in a location like that, rather than solder, is that the wire harness there can be subject to vibration, and solder wicking along the wire makes it stiff. (They do, of course, use solder in lots of places where that isn't an issue, like on circuit boards inside modules where everything's fixed in place. Just not where the wiring gets shaken.)