Looking for some advice with what I think is a voltage gauge issue that when truck is running gauge stays in the high end of the yellow range, never goes into the green range. New belts, new drivers side alternator, 2 new Optima Red Tops. With truck off, front battery voltage is 12.5 and rear battery voltage at block on firewall is 25.2. With truck running with slight acceleration front battery voltage is 14.9 and rear battery voltage is 30. I believe this tells me that both alternators are working, correct? Voltage gauge remains in the high yellow range. Any suggestions?