Is my alternator bad??

[ExplicitUrSelf 10+ year member]

I have a 2001 Blazer 4 door 4.3L 2WD and i think my alternator is bad. The things i have nticed are when i have the car at idle and i give it gas to about 3000RPM and let it go, the volts according to the gauge cluster go from 14.16 down to 13 volts and then it jumps back to 14.13-16 on idle. Another thing that i have noticed is i have a 1000watt RMS car audio systm and when i have my music up decently loud. My sub cuts out until i lower the volume a bit. The battery i have unde the hood is a brand new optima yellow top. The one with the light grey casing. I also have the big 3 upgrade using 1/0 tsunami oxygen free compotion power wire. My grounds on my amps are good. Full contact to metal. I sanded down the paint where i have them bolted to. What do you guys think i should do?? I belive the stock alternator is 100 amps. I was thinking to jumping to a 120 amp alternator or problobly even a 140 amp alternator. Input would be great. THNX

Click to read more...

 

[Crownvicon28s 10+ year member]

I dont think your alt is bad. When mine went out my voltage meter dropped to the battery voltage and didn't go up no matter what rpms I reved to. Some cars will cut off and not start if the alt goes out. My car does the same thing when I rev it up and take my foot off of the gas. Is your voltage dropping really low when you turn your music up? From reading what you have I would think you would be ok with 1k watts.

 

[Slo_Ride 5,000+ posts]

You can have your alt tested at your local auto parts store.

 

[azphat12 10+ year member]

Yea take the car to an Autozone or something and have them test the alternator...

That would be an easy solution...

 

[DammitJames 10+ year member]

You can have your alt tested at your local auto parts store.

this then come back and share the results they will do it for free