Trooper Voltage

My 1996 Isuzu Trooper has had some interesting things going on.
Basically my tranny goes into "Limp home mode" and I got a B-solenoid error code. I cleared the error code and the tranny works fine for 8 months. I then get the same tranny symptom but this time I get an error code "Mass air flow". I clear the error code and the tranny works fine again. I notice that the voltage regulator is showing 14V but drops to 12 or 11 volts under acceleration unless the head lights are on then it stays at 14v. I replace the alternator and the voltage regulator still shows the same thing "drops from 14v to about 11 or 12v. Anthony described that his 1995 Rodeo voltage drops in the same way and that the electrical system was designed that way. Is this dropping voltage under acceleration common or just an Isuzu thing?

Thanks

1996 Isuzu Truck Trooper V6-3165cc 3.2L SOHC (6VD1)

Vehicle Level (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741) http://library.alldatapro.com/images/a_003366.gif Starting and Charging (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741/34863246) http://library.alldatapro.com/images/a_003366.gif Charging System (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741/34863246/34863337) http://library.alldatapro.com/images/a_003366.gif Alternator (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741/34863246/34863337/34863338) http://library.alldatapro.com/images/a_003366.gif Technical Service Bulletins (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741/34863246/34863337/34863338/34850921) http://library.alldatapro.com/images/arrow1.gif Voltmeter - Needle Drop During Hard/Quick Acceleration (http://library.alldatapro.com/alldata/LIB~C23815~R0~OD~N/0/41746574/56623470/56623476/56623477/34853741/34863246/34863337/34863338/34850921/74626363) http://library.alldatapro.com/images/arrow2.gifhttp://library.alldatapro.com/images/blnk_spc.gifVoltmeter - Needle Drop During Hard/Quick AccelerationBULLETIN NUMBER
SB96-04-L002
ISSUE DATE
FEBRUARY 1996
GROUP
ELECTRICAL
1996 TROOPER (UX) AND RODEO (UC) VOLTMETER NEEDLE
DROP DURING HARD/QUICK ACCELERATION
AFFECTED VEHICLES
1996 Trooper (UX) and Rodeo (UC) models.
SERVICE INFORMATION
On all affected vehicles, the instrument panel voltmeter needle will drop during hard/quick acceleration. This voltmeter needle drop is normal and is not indicative of a condition requiring repair.
1996 vehicles are equipped with an alternator that is designed to stop charging during certain engine speed modes in order to lessen engine load. At idle, the alternator will output approximately 14.3 volts. During a slow/steady acceleration, the alternator will remain at a 14.3 volt output. However, during a hard/quick acceleration, the alternator output will drop to 12.7 volts. The alternator will continue this 12.7 volt output, until the Powertrain Control Module (PCM) detects a drop in engine speed, at which time, it will return the alternator output to 14.3 volts.