Alt putting out above 14V till air and or headlights turned on, then alt falls to below batt volts. Showing 11 volt 4.2amp draw between batt neg post and battery neg terminal while disconnected. Draw only goes away when rev light and condenser fan fuse is pulled at same time. Pulledone at a time only a slight drop. Car is stock. Is this an alt testing good but goes bad under load or to much of an draw on battery..... ?All Intelligentwelcomed.

Well it depend on that alternators specs but really it should not have more then 13.7 or 13.9 volts tops coming from it.So my thought for sure is the alternators regulating circuit is not working right therefore needs to be replaced but take note that not always is the regulating circuit inside the alternator many vehicles now a days it is inside of the main comp=ECM or can be mounted under hood.Keep in mind that the alternator itself could be at fault here.
For sure if the load causes the current to drop below 13 to 12.5 volts that would affect all the draw of any devices that r needed or turned on. Example the head-lites would be dimmer so would the interior lights & the engines idle would drop especially if engine is cold.Plus the idle would vary once different devices were turned on or off.

Hope that helps & best of luck.By the way the basic rule here is if the alternator gives out more then 14 volts for sure check on the alternators specs but more then likely the alternator is faulty unless extra features or devices or modifcations were made & upgrades were made. Example a special A/C outlet was added that require a special alternator upgrade.

Sounds like too much draw on battery. Your alternator must maintain at least 13.5v to recharge your battery at all times.

You may need a new voltage regulator for your alternator or your headlight bulbs are very high wattage and demanding too much current.

Good luck!