L28 Alternator Connections

Table of Contents

Info sourced from: http://www.outerlimits4x4.com/ftopic104473.php

Label Function Harness Wire Colour About
B / BAT +12V Power White/Red Straight connection to the + post of the battery. This wire is a larger gauge than the other connections. This is the wire that the alternator uses to charge the battery. You can run a larger wire to the battery if you don’t trust your old factory harness. A bigger wire would probably be better if you go to a high output alternator. This is a separate post on the back of the alternator with a plastic/rubber isolator to keep it from grounding to the alternator chassis.
E Ground/Earth Black Connection to chassis ground/earth. The alternator should have a good ground through the block but this is a safety measure. Most cars are fine without this connection but it can be hooked up regardless. This is a separate post on the back of the alternator.
S Voltage Sense Yellow Needs to see the battery voltage so that the alternator knows when to do its thing. This is the top of the ’T’ connector on the back of the alternator.
L Charge Lamp White/Black Wired directly to the charge lamp. The other side of the charge lamp goes through the fuse box to a + ignition source. This is the bottom of the ’T’ connector on the back of the alternator.
P Tach/Accessory N/A An extra connection that is an output to tachometers that were used on the 280ZX cars. It does not need to be used on earlier Z cars. A 1978 Z/ZX alternator sourced from a parts store will have the ‘P’ connector, which the stock MQ alternator does not have. 1978 - 1983 Z/ZX vehicles use the same alternator.