High battery voltage

[1slowdsm]

So I was leaving my parent's house to go get some gas then head home. Turned out of alley, then saw my gauges glow brighter than normal and thought it was just the street lights 'cause it went back to normal. Then got gas, started heading home, got onto the highway and saw my Temp gauge shoot near the red part and gauge lights were super bright (including headlights). So I went back to parents' house, could not find a flashlight (they're moving so a lot of things were gone). So I use my stupid cell phone light. Checked the alternator belt as best I could, felt to see if it was too tight/loose and it seemed fine. Battery seemed/looked like normal. Coolant was still full. So I headed home and every once in a while when I start to speed up the same thing happens. My logger read up to 18.4v, but COOL was still at 213.1 like usual yet my TEMP gauge was getting near the red mark scarying me. This also happens when I blast the A/C while cruising on the highway home, but it never happens when I blast the A/C at a dead stop. Only seems to happen when I accelerate, then after about 10 nerver wrecking seconds it'll go back to the normal 14.2 or so volts and lights go normal again.
I'm not very good when it comes to electrical stuff, so ideas of what it could be or what I could check let me know asap. I think if my car goes dead again it'll be the last time I drive it/own it :(.

[Swifty1638]

Not sure why the temp gauge would spike like that unless there's a wiring glitch there too, causing the sending unit to send false voltages (I think it reads 0-5 ohms resistance?) anyway, sounds like the capacitors in the alternator are bad. Switch it out with a new one, check your fuses, and that should be ok.

-A. Swift

[1slowdsm]

I would've never figured that one out, that the capacitors in the alternator are bad. You mean to switch out the alternator or just the capacitors? I seem to be going through alternators more than anything else. Will I be ok to drive the car still or will fuses and stuff start blowing? But anyway, thanks for the help.

[Matt D.]

I wouldn't say the capacitors in the alternator are bad, but the voltage regulator in the alternator is bad. It's the same thing that goes bad when your alternator stops charging. Take it out and have it tested somewhere, or just pay to put a new one in for piece of mind.

[Swifty1638]

I meant voltage regulator. Damnit. With all the lessons in school on alternators and starters, you'd think I could have remembered the CORRECT term.

-A. Swift

[1slowdsm]

guess I'll be having it tested first to see if I really need a new one. It hasnt even been a year since I've put this current alternator in and now it might need a new one already.

[Swifty1638]

Where'd you get it? Napa? if so, that's why. I don't know how many alternators ive put into various customer cars, only to have them come back with a dead battery, or blown fuses due to a poor quality standard the alternators lived up to.

-A. Swift

[TsiEagleTalon92]

So where do you suggest going out and getting one at? I think I need to buy 2 new ones.

[Super Bleeder!!]

Bosch or mitsu

[DBMajik]

I'd get that thing out of the car ASAP. One of my buddy's alternator was going at 18 volts and blew up the battery in the back of his car since it was relocated. Wouldn't be fun cleaning up acid in the engine bay either.