[save_old_iron]

there is little to go wrong mechanically, but electrically, 99% of the time its the aging and decay of the tungsten coated relay contacts that promote most of the failures.

externally, the unprotected flexible braided ground wire spanning the mounting bracket to the regulator body will eventually corrode away and the rubber mounts can deteriorate to the point the engine vibration can affect the operation of the relays or strain and further degrade the ground strap.

external to the regulator unit, wiring faults account for most of the failures

if you do not put the sealing gasket back on the cover of the unit, hydrocarbon vapors will get inside the regulator housing quicker and accelerate the corrosion of the relay contacts

if you could find the little relay contact buttons for sale, and press fit new contacts into the relay arms, you could renew and adjust the regulators back to near new performance

if anyone is interested, I can post a detailed but easy to understand explanation of how they work.