I have been having problems with the headlights and dashlights flashing on 2000 Nissan Xterra

This happens once the truck warms up about 2 weeks ago I went out and started the trk to warm it up just as I got to it it went dead and i had to boost it the same thing happened today. I had the battery and Alt tested on the trk at high idle it showed 13.8 volts. I have no idea where to start.

by in Water Valley, MS on December 08, 2011
1 answer
ANSWER by on December 09, 2011
I think the alternator has problem anyway.The alternators has diods in it anywhere from 6 to 9 in most cases. If one of them goes out you still have some charge but DC pwer gets to electrikal system that causing flashing and even damaging the battery.