dead batt symptoms???

On my 73 baja. .
It seems when. The batt is weak Not Dead. The lights and radi works but it will not turn over. Absolutely wont even try to turn the starter at all, but with a jump or fresh battery it turns over fine. It seems my engine only turns with a full charge. I never have a slow rurn over like ive experienced with any other vehicle. And the alt light does not come on unless im runnin headlight and 2 12s on a 1000 watt amp it will slightly glow so i assume it is charging.
It reminds me of my 18 volt dewalt set with lithium batts. They give no warning of a weak charge. They turj full bore or they dont spin at all.
Is this normal or :s this the sign of a bad solenoid or starter that only works with a full charge? I habe a brand new batt but have had this effect with other batts.?

One problem could be your stereo system. I'm assuming your amp is wired with a remote power wire that turns it on when the ignition is turned on. Stereo amps draw a lot of power. You may want to install a capacitor in the system so that it will draw power from the cap instead of your vehicles system. One way to check and see if this is the problem is to pull the inline fuse (if installed) from the power wire to amp. Then try and see if you have the same issues.

My dad had the same problem with his truck recently. Battery had enought juice to keep everything running but not enough amps to push the starter.

Remote wire is coming off the radio. Radio is straight wired bypassing the ignition. It is only on if you turn it on and the amp turns on only when the stereo is on.
Alternator going to put out the standard 14volts or so?

Wirings bad buy a hard start solenoid from napa ST 1 will fix it. This will allow key to engage solenoid and then that will power starter making a shorter path. I see it a lot of times in late model bugs. This cuts wiring path from 18 ft to about a foot. The glowing alt light with a full heavy load means yout alt is to small and cable from alt back to battery is too small also and check and clean your grounds.

http://www.madelectrical.com/index.shtml

Ill have to check into that solenoid thanks. .
Did a little research with a volt meter and didnt come.up with anything helpful. I had 12.7 across the batt unhooked. 12.6.with the cables on. And about 13.5 with the car idling.

did you read voltage with amps and radio on, i had a bad diode in a alt. before put out right voltage till you turned on headlights then it pulled battery voltage down to low to crank car.would run fine till night came,