Alt squeal after amp inst

95 Eclipse GST. This has been an ongoing problem for awhile. When an amp is hooked up to the battery the belt will start spinning around the alternator and produce a squealing sound. This is the 3 alternator and as many different amps in the 600W range. I have 1/0 wire running from the amp to the + post on the battery and all of the grounds have been cleaned up (1/0 for the amp ground also). When you take the wire off the battery the squealing goes away, no load on the battery. After you drive for about 10 seconds the the squealing goes away till the next time you start the car hot or cold. The positive wire to the amp is not grounding out on the chassis. I used a multi-meter and checked to make sure it was open.

I'm thinking its time for the Big 3. Any thoughts? This is my first real stumper in 30 years hooking up stereos.

it squeals like that because you are putting a high load on it. Do you have a cap on the system ? Something you are connecting up with the stereo system is drawing a lot of power. Do you have a way of measuring the current draw when the car AND stereo are off ?

One of the things I over looked. Need to see what the amp draw is.

Check the drive belt tension on your alternator, what I think your hearing is belt squeal from the belt slipping on the alternator pulley from the added drag caused by the alternator pumping out amperage to recharge the battery drain from starting the vehicle plus the electrical load the vehicle needs to run and power accessories (and your new amp), then when the battery is charged (that 10 minute span you referr to) the draw is less and the alternator drag is less and the belt quits slipping.

If your engine has one of those auto tensioners (spring loaded arm with a pulley) then you may want to try replacing the belt (A belt can still look good but the belt surface is worn to the point it dosn't grip the pulley properly and slip) or possibly the tensioner spring is weak and not keeping proper tension on the belt causing it to slip, in which case replacing the tensioner may be the cure.