All at once my brake light, battery and A/T light came on. Also my battery gaug on 1997 Mitsubishi Montero Sport

went all the way the to past 16V, which on this car is over charging. The digital compass and tempeture would go off and on. When ever I can to a stop light and was just setting, not under throttle it would all go back to normal. Does anyone have a clue what would be caudsing this?

have the charging system ck'd out,sounds like the alt is not charging at idle
Thank you, I will be taking in on Saturday. Hope it won't cost an arm and leg.
1 more answer , 1 more comment
needs an alternator..over power is causing the dash relays to light up
Thank you for your help.
I will be taking it in on Saturday.