my altenator has 14.4 volts but when i put under load it squeels very loud

Slipping belt?

No i dont think so i jyst replaced tension assembly and the belt last week

I took it to o'rielys put tester on it altenator was at 14.4 volts put it under load and it squeels badly...squeels mostly in the am when lights heat are on some through out the day...

Still sounds like a belt, do this turn the switch on put heater fan on high headlites on bright and wait for the battery go down a little then start the engine and gun it a bit to cause the squeel after it stops squeeling turn switch off then carefully feel the alternator pulley if it's super hot you have a slipping belt if it's not hot have alternator bearings changed

IF it is not the belt you need a new alternator. Maybe a bearing is bad.