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the metal mount bracket is the ground
The 1990 Chevrolet Corvette IAT sensor does have two wires. The sensor has a ground wire and a positive wire.
my wipers quit working, got a new wiper motor , it did not work either, found out that it has lost ground, attached a ground wire to engine and wiper motor and it worked.
the hot wire goes to the starter and the ground wire bolts to the engine block.
The battery ground wire runs from the battery to the engine block.
There is no ground wire.... it grounds through where it touches the engine
The ground wire leads from the negative side of the battery and connects either to the engine block or to the frame of the automobile.
ground issue on wiper motor housing
The ground wire on a Sportster engine is typically connected to the engine case itself or to a designated ground stud on the engine. It is important to ensure a good metal-to-metal connection to provide proper grounding for the electrical system.
The ground wire on a 1981 Corvette typically connects to the chassis of the vehicle near the gauge panel. It is important to ensure a solid connection to the bare metal of the chassis to provide a good ground for the gauges to function properly. Make sure the connection is clean and free from corrosion to prevent any electrical issues.
Remove the spark plug wire from the spark plug. Use some heavy gloves or a set of insulated pliers to hold the spark plug wire about 1/4-inch from the engine block (ground) and crank the engine - you should see a spark jump from the wire to the engine ground. For a better check, use another spark plug and put it on the spark plug wire and use it as a "jumper" from the wire to the engine ground.