Knowledge dump: rebuilding starter solenoid connector plug

Problem

Starters for first generation Tacoma's vary in size. Aftermarket starters are often smaller than Denso starters. Consequently, factory solenoid connector plugs might not reach aftermarket starters. It is common for lay mechanics to haphazardly connect the female and male connectors using a DIY connection terminated with male and female spades. In other words, bridge the gap between the starter solenoid and wiring harness with a jerry rigged wire extension. These connections are rarely protected with a sealing epoxy compound, meaning they are exposed to the elements and easily dislodged by vibration or disruption. Crucially, insufficient wire gauges are common as well. Either way, these mistakes present fire risk.

Separately, the factory battery cable harness is woefully inadequate. The battery-negative to body connection uses a pitiful 16 gauge wire for example. In addition to alternator limitations, the battery cables and harnesses will become a pain-point when adding electric fans, light bars, etc. Since the OEM battery cable harness and starter solenoid harness are joined, and because the OEM starter solenoid harness is surely old and crusty, meaning that reusing wires is ill-advised, anyone looking to rebuild the battery cable harness will need a strategy for completely rebuilding the starter solenoid harness.

The purpose of this thread is to give you the information which you need in order to properly extend the starter solenoid wiring harness.

Solution

The connector housing (TS187) is part number 90980-11400.

The female terminal you need is part number 82998-12480; it is a Sumitomo 4.8mm sealed female terminal which accepts 10-12 gauge wire.

The wire seal you need is a 4.8mm single wire seal with 3.6-4mm insulation diameter.

If you prefer not to purchase these components individually then you can find rebuild kits on Amazon.

Obviously, you will also need (high quality) 10-12 gauge wire and all of the necessary tools and components (crimper, wire stripper, heat gun, double-wall heat shrink, expandable braided sleeving or heat shrink sheathing, etc) to finish this project.