Hi Andrew,
Yes, that’s disconcerting, especially if it’s an intermittant problem.
On a cascade of easiest to most difficult troubleshooting ladder, I would look very closely at the wiring at the alternator; are the crimps on the terminals secure; Is the alternator ground wire securely connected; are there any “hot spots” in the wiring–spots that are discolored–look where wires are clamped in the wire run.
While at the alternator, check to see that that segments — pulley end; middle, and wire connection end are secure and tight against each other. There have been service bulletins stating that the through bolts were not tightened to the correct torque during final assembly.
Do you know how many hours are on that alternator?
There are definitive trouble shooting instructions in the service manual. I’ve scanned a few pages; they’re attached to my reply.
The 60 amp alternator is Prestolite alternator
The 90 amp alternator is a Ford alternator.
The puzzling part is the system was restored once when you cycled the alternator switch, but that didn’t restore it later.
That logically could indicate that there’s a problem with the alternator switch. The part number for the switch is 688 296–this on off switch is used throughout the Piper single engine line; there’s a cap on the switch face to ID the circuit.
You can see a picture of the 688 296 switch here: https://www.ebay.com/p/1729757859.
It’s a two position (on off) switch with two connection options-left and right. I suggest you or your mechanic check to see that the wires are tight, and that the connectors at the back of the switch are secure. If one side is secure and the other isn’t, you can swap the wires from one side to the other.
I’ve just outlined some of the steps I would take if I were running down an intermittant fault like this. If it’s one of the things I’ve noted, count yourself lucky. Sometimes the TS struggle boils down to testing each wire individually.
Good luck, and let me know what you find, or if you need further suggestions.
Steve
