My 60 Amp Alternator Notes. 60 Amp alternator has two studs under the cover and a pigtail wire. It also has a grounding point on the case. Seems to be the most common set up ?? and sometime the wiring is a bit confusing.
For simplicity... 60 Amp units, Ground is the ground bolt hole on top. More on this later.
Under the cover the Small Stud connection is Switched 24 volts from the PCB in the Run Position. Think of it as the field or to energize the alternator.
Under the cover the Large Stud is the positive regulated output to the batteries. BUT NOT directly. This lead terminates to the very large positive stud on the starter, then to the feed-thru bolt in the tunnel then to the batteries. Note this large alternator stud also acts as a fuse-able device should something go POOF on the output.
The short pig-tail lead (packard connector) is the AC SENSE. It outputs a raw single phase AC voltage. When the alternator reaches proper RPM this AC frequency (engine now running) is detected by the PCB and it LOCKS OUT the starter, preventing a starter re-engagement. It also supplies this voltage to the TCM to warm a bi-metal thermal switch or solid state circuit in later TCM's (along with increasing engine water temperature) to manage the "After Glow" circuit in the PCB. Other PCB circuits manage, to cycle glow plugs, wait light and all the things that can go wrong in the PCB. Starter LOCK-OUT is a test if you'er up to it.
"Ground is ground" and this is NOT ALWAYS true on the HMMWV or anything else for that matter. If you have followed the threads here you know of the problem grounds.
If you study the schematics, you will find multiple in harness splices. (I have cut them open) Places where factory spliced grounds and positive leads (all bundled up in the wire loom) bringing together circuits for lights, controls, gauges, and grounds etc. to a common lead that you can SEE and get to. Just note, if your having crazy electrical headaches it's something to think about. The "grounding kit" helps to eliminate some of the IMO poorly designed electrical goings on.
Hope this helps with the 60 amp-er.
Ready to test the anti-starter-grind circuit?
CAM