Charging Problem

[sstephens901]

I have a 1988 F250 xlt lariat, I was driving along and the alternator blew up, however, after replacing with a new one, and checking the battery I noticed that the gauge inside the dash still read that there was no charge entering the battery, I know the alternator is good, and so is the battery. I'm not sure how to check any of the towing equipment to see if that is interfering, or if it even would. An I also already bough the new pig tail for the alternator wiring and have put it on. Any suggestions as to what is stopping the battery from charging?

[1972hiboy]

first thing is first. put a multimeter set on the DC 10-20v scale and put the red lead on the + terminal on the battery and the black lead on the - terminal on the battery and see what the multimeter says while the engine is running. If you have 12.80--14vdc then your charging. If your voltage ready is below 12.50 thats not adequate to charge. If your reading is above 12.80 volts you may want to check the alternator with a ociliscope to see if the diodes are functioning correctly. you can lose a couple diodes and the output voltage will be good but it will set off the charge warning light and not charge the battery correctly.