[LH Lead-Foot]

I believe the alternators "L" terminal begins at the key switch. When on ACC, it provides B+ to the dash light. That bulb is a 194 peanut bulb, and when lite, it's resistance drop to about 460 ohms. This make is a current limiting device. To apply a full 12 volts dc to the "L" terminal, will blow out the regulator. The CS alternator used a "Delta" style stator or called "Y" connect. The single connection is ground when the alternator is off or not working. But let's say, it's just off. It provide ground to the dash light and with B+ coming from the key switch, the build is on. Once started, the alternator's "Y" terminal becomes hot. Now you have B+ from the alternator to the dash bulb & B+ coming from the key, then bulb goes out. The normal reason for the dash bulb to come on, either bright or dim, is usually because the Diode Trio inside the alternator has a bad diode in it. It sole job is to feed the regulator with voltage so it can use the "Sense" input to control the field magnetic strength by controlling the ground side at 400 hz. The stronger the field, the higher the output.
Diagnostics. Unplug the alternators connector and have a fused jumper wire and digital multi meter handy on volts DC. With the key-on / engine off, a check with the DMM will show B+ or battery available. So good.

The use of a 460 ohm 1/2 watt resistor used in series from the key switch will work the same way the dash bulb does now. On passenger cars, for years, they wired a 460 ohm resistor in parallel with the bulb. Bulb goes out, reduced current at B+ still allows the alternator to work.

With key-on / engine-off, if you have B+, then install a fused jumper wire to the lights wire. This will make the bulb come on steady. Good. You have tested the dash light circuit.

I believe you said the bulb was blinking, even thought I have never seen that, but if it passes the above test, the problem is in the alternator. Easy fix with front / rear bearing, new brushes and a diode trio.

The resistor inside the alternator that is removed during repairs, is a wire-wound resistive wire, around a ceramic core, but it's job is to sense temperature. When hotter outside, charge voltage is reduced. When cold, it increase the charge rate. Therefore, the readings during seasons will show between 13.2 - 14.2 volts DC.

Their should be no reason to suspect the voltage regulator, but is you want to test it. prepare the DMM, set to Volts DC, place on the battery. Look on the back case of the alternator for a case hold shaped like the letter "D". This window allows a pocket flat blade screwdriver to hit the voltage regulators ground tab, while grounding the screwdriver on the case to the alternator. This will full-field the alternator and with the engine rev'd up, the voltage at the battery will increase along with a whining alternator. It is at this point where a digital readout amp clamp will show within 10% of the alternators output. If rated at 80 amps, you'l commonly get 70 amps.

Rebuilding the alternator is something many do not do anymore, because boxes of alternators are found everywhere. They test each component (In Theory), clean everything, put new brushes & bearings, test it and call it a day. This is called "Spray & Pray"
Good luck.