I have found the rivits holding the blade/spade on the switch loose and cuased it to heat up burning the plastic plug on them before.

low idle and alt output does not help anything either.

I now idle my trucks up at night with lights on till it has the no dim headlights at idle.

only a couple hundred rpm over what I like but no more discharging at a redlight at night.

I think I will go have a look at the switch in my 85 truck now... it is 29 yrs old