I have an 8yr old Trane TTB042D100A 3 1/2 ton outdoor unit that suddenly died and will trip the breaker INSTANTLY when it starts. No hum or anything. Was working perfectly before. Wiring, low voltage, etc, checks ok.

The GE cap looks good and specs out 5/40uf.

There are no shorts to the case or lines from the terminals, but the compressor windings measure around 1 ohm or .2 ohms depending on which terminals you measure. Seems low, but I don't know the spec.

This is the tricky part, usually there is a short to the case that would cause the trip. That is why I still have hope.

Do you think a start kit can help this or its time for a new compressor? One tech said if it kills the breaker instantly its finished. Is it possible for a cap to spec out and cause this issue?

There may have been surges cause other electronic things were ruined around that time, but the A/C could be coincidental.