I put a new starter on a year ago. today put on anew alternator and my truck will only turn over a few times quit

Sounds like a dead battery
have a load test done on the battery
reading voltage with a multimeter gives a wrong indication of the capacity of the battery as it will read 12 volts but under load ( such as starting) that voltage can drop to under 5 volts with a bad battery
Good batteries under load will not drop to less than 11 volts

Battery ? battery cables ? Test the starting system , voltage drop starting system ! go on you tube a check out voltage drop testing starting system .