Help! My 98 GT's got a low-voltage problem
 

I've looked all over and this problem may be posted. If so, please reply with the page link and I'll get it. thanks!

I was idling at a busy (loud) traffic light last week when a louder howl started and I eventually realized it was under my hood (no mods). I turned off the A/c but no change. Before I could gas it the howling stopped, but my volt meter apparently had dipped low and was now coming up. It had been rock-solid above mid-meter, now it is below mid and fluctuating with engine speed and temp (perfect volts when engine is cold). Took the car to Advance and they put their tester on in, read low @ 13.3 volts, but diodes were OK. I replaced the alternator anyway, but no change.
The car starts weakly: not the usual VARRRRROOOOMMMM I like, and it stumbles on acceleration and lugging.
So my meter agrees with tester, the car has 138K miles, the battery is a Diehrd, 1 yr old, plugs and wires all 3 months old. Alt is new as of Saturday AM. Volts are slightly lower now than before swap.
anybody seen this before?

thankuthankuthanku

RE: Help! My 98 GT's got a low-voltage problem
 

have you had your battery tested? sometimes you can have a dead cell in the battery. how about battery cables? r they in good shape? maybe need replaced. not sure about the sound you heard. don't know if this helps, but it's a start. anyone else have ideas?

RE: Help! My 98 GT's got a low-voltage problem
 

edit, i posted the same thing too, no need for redundency