Tacoma alternator

There are lots of ground wires. Many of them are there just to be safe and you might not miss them. How is the car working? Are you having any problems? If it's running ok, just go back to the shop and ask them to reconnect that wire.

Also be aware that there are many wires hanging loose under the hood that aren't always used. In general, if there is a plastic connector on the end of the wire, chances are it is used when there is some option that isn't on your vehicle. If the wire has a round loop-type terminal on the end, it was likely bolted to the engine, body, or some component. Some of those are only used to reduce noise that might radiate into the radio antenna.

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