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Starter Wiring

53K views 2 replies 2 participants last post by  smokey626 
#1 ·
Howdy folks! I just got a new mini starter from Jegs to replace the old one. The old starter solenoid has 3 terminals, one for the battery, one marked "R" and the other is marked "S". The new mini starter only has a battery terminal and one small unmarked terminal. Which wire do I connect there, the one from the "R" terminal or the one from the "S" terminal? And what does the other wire do anyway? What do the "R" and "S" mean? And what do I do with it? HELP!!! *insert pulling out hair here* :confused: Thanks in advance!
 
#2 ·
smokey626 said:
Howdy folks! I just got a new mini starter from Jegs to replace the old one. The old starter solenoid has 3 terminals, one for the battery, one marked "R" and the other is marked "S". The new mini starter only has a battery terminal and one small unmarked terminal. Which wire do I connect there, the one from the "R" terminal or the one from the "S" terminal? And what does the other wire do anyway? What do the "R" and "S" mean? And what do I do with it? HELP!!! *insert pulling out hair here* :confused: Thanks in advance!
The unmarked terminal on the new starter is the same as the "S" terminal on the old one.

The "S" stands for Start, and the "R" stands for Resistor, I believe.

The S terminal is wired to the start terminal on the ignition switch. If the vehicle is equipped with a neutral safety switch, it will also be in this circuit. Applying voltage to the S terminal trips the starter.

The R terminal is wired directly to the + terminal on the ignition coil, or to the coil side of the ballast resistor. The function of the R terminal is to supply full battery voltage to the ignition coil during startup. The R terminal goes dead as soon as the starter is disengaged. Once the engine is started, the ignition coils in most old cars get powered either through a ballast resistor, or a resistor wire that drop the voltage to the coil down to about 7-8 volts.

When the starter is disengaged, the R terminal is isolated from the S terminal so power from the coil doesn't back-feed through the starter solenoid. You wouldn't want to just put both wires on the S terminal.

If your car has an upgraded ignition coil that does not require a ballast resistor or resistor wire, the R wire is no longer necessary and can be removed or taped up and abandoned in the harness.

If your car does have a ballast resistor or resistor wire, and you want to retain the functionality that the old R terminal provided, you will need to use a relay. But you may find that your car starts fine even without this feature. In which case, you could tape up the R wire and forget about it.

Good Luck :thumbup:

Joe G.
 
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