What are the three wires going to the alternator?
Remote voltage sense alternators: The three wires connected to the alternator are the positive, negative cables and a third smaller gauge wire connected to the alternator remote sense or (S) terminal. To determine if your vehicle has remote sense, voltage will always be present on this terminal at all times.
What would cause an alternator to keep going out?
Mechanically a pulley could be off-center and strain the alternator bearings. Or in older cars the tensioner may be adjusted too tightly. If it’s an electrical death, it could be using alternators from a poor source, like some of the marginal alternator recyclers.
Should alternator have power with key off?
No alternator should be hot to the touch after sitting for a while. With everything shut off in the car disconnect the positive battery cable and with a meter hooked between the cable and the battery see if there is any voltage. If so start disconnecting or pull fuses one at a time till the draw is gone.
Where does the wire go in an alternator?
Check if your alternator has a terminal marked “Ign” or “L.” The terminal is smaller than the previous two. The wire that attaches to this terminal can vary in color and the opposite end goes to the ignition and/or dashboard warnings system. Most typical alternators have this wire connection.
How does the voltage of an alternator affect the battery?
If you are able to look at a manufacturer’s diagram of the alternator’s connectors, the wire that slides over Pin 1 of the alternator leads to the positive (+) connection on the vehicle’s battery and senses voltage. If the voltage rises above or falls below 12 Volts, the alternator’s internal voltage increases or reduces power output…
Is there a fourth terminal on an alternator?
Most typical alternators have this wire connection. Check to see if you have a fourth connection on your alternator. The fourth connection is used to wire between the alternator and the voltage regulator. Labeling is inconsistent but is often “S”. If you have a fourth terminal it is for the voltage regulator.
What to do if your alternator has bad ground?
Place the red lead on the positive battery terminal (if possible dig it into the battery post, not the terminal). Place the black lead on the bad post of the alternator. Same thing as above, if the voltage is above 0.5v then examine the positive cabling for problems.