Replaced alternator, fuses, temperature control sensor, the plug that goes to the alternator and battery. The battery light comes on a few minutes after crank. We check the voltage on alternator and it was only putting out about 7.30-8. Volts. Replaced a fuse and the volts jumped up to 14.5 volts. Battery light went off but once I turned on the lights and got the car rpms to 2 the battery light came back on and the volts dropped down to 7.3. We have check wires and cables and cannot figure out why the alternator is now only putting out half the voltage. I don't know what else to do.. any suggestions?