big volts

barbee6043 said

I made 2 changes earlier today. I put a fresh battery in it, and replaced the starter relay, ( told in previous thread this can cause elect. problems).

I turned on the lights, heater motor, moderate to fairly high reves, readings: batt + : 12.2 alt. output stud 12.1 , and at idle : batt + 12.2 alt 11.9

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If those reading are correct then the alternator is not charging. When the alternator is charging the voltage at the output stud should be higher than the engine off battery voltage. It sounds like the car is running on the battery only. If the voltage regulator is only seeing about 12 volts on the blue wire it should be increasing the alternator field duty cycle to increase the voltage.

Here is what I would do. Hook your meter to the battery and note the voltage reading with the engine running. There should be two small field wires on the rear of the alternator, one dark blue and one green. With the engine running test the blue wire to be sure it is essentially the same as voltage at the battery. Then test the green wire and note the voltage. It should have some voltage greater than zero, typically between 4 and 11 volts depending on engine speed and electrical load. These are the wires that come from the voltage regulator. Test at the alternator, not the regulator.

Almost forgot, a fully charged battery should be at 12.6 to 12.8 volts with the engine off. Substantially less than that means the battery is discharged to some degree.