1986 dodge daytona voltage problem

with the engine running use a volt meter to check battery voltage with the head lights on, should be around 14 volts on a 12 volt system, if 12 volts or less the regulator or alternator is at fault . if around 14 volts there is a drain or short, the battery could also be faulty.

The way to check for an over or under charge is to connect your volt meter to the battery, before starting the vehicle.
You should have a reading of 12.5 to 13 volts. If it's 11.8 like you stated or less, it means battery is not fully charged, or it's bad. Now start the car & check voltage again while running the engine, the voltage should exceed 14+ volts, this means your Alternator is charging, the voltage should drop after battery has been charging for awhile. When you turn the engine off after letting it charge the battery, & if the battery is good, you should now have 12.5 volts to 13 volts.
Now to answer your question, the Voltage Regulator is inside of the Altenator, I believe you xcan take the alternator apart to replace it, or simpler to just replace the complete alternator.

Your description does not rule out a bad battery. Make sure the cable connections are clean and connected correctly. Assuming this is all good check the voltage with a DC volt meter. A fully charged battery should test 12.85 Volts. If it is very near 12 or lower it is a week battery. With jumper cables or other means to get good voltage try and start it again. If is start you have a bad or week battery. If you get it to run check the voltage again while it is running. The meter should now read 13.5 -14.0 volts. If not above 13 volts it is not charging properly causing the battery to run down.....................

if the battery light is on while running the charging system is not working.you can check
with a volt meter,setting meter to dc volts & connect meter leads to battery.reading should
be 13.2 - 14.5 volts if lower than this your only reading battery voltage.check single red wire to the alternator it should read battery volts 12v.if battery voltage is present than alternator is faulty,if no voltage reading you'll need to trace & repair the wiring
note; battery should be fully charge before testing

good luck

The older chrysler products have a ballast resister on the firewall that is used for dropping the voltage to the ignition coil. During a start procedure, while the key is turned all the way in start position 12 volts bypass the resistor forcing a high output of coil voltage. When you release the key to the run position 12 volts goes ito the resistor & a lower voltage of around 6-7 volts comes out, & goes to the coil.
What happens, is the resistor breaks inside and no voltage is coming out the resistor. Thus only a start condition exist with no run.

You need to get a volt meter on it. Your battery should be around high 12 to 13 volts while not running, and increase a little without going over 14 1/2 volts running.

The alternator may not be charging the battery. Jump start it, and use a volt meter at the battery, red lead to positive and black to neg. The meter should read between 13 and almost 15 volts, any lower than 13 volts, the alternator is no good. (this is done with vehicle running).

With volt meter on battery start car and read voltage. When yo first put the meter on a full charged battery it should read between 13-15 volts. When you first start motor the voltage should go 3-4volts higher then when you first put it on. And then tapper down after awhile. If there is no voltage increase after start alternator is out.

change your alternater

if it is not idleing right the volt meter will go up and down is it fuel injected or carb?