Okay so I haven't driven my truck in like a week. I went outside yesterday and it woudln't start so I jumped it and drove around for like half an hour to let the battery charge. I tried to leave this morning to go to my interview and it wouldn't start agian. So i took the gf's car. I picked up a multimeter on the way home and tested the battery. It was at 10.92V(after i got it started it was like 14.2V). still wouldn't start so I jumped it again. Then it wouldn't idle. Just turned back off. So I sat there with my foot on the gas for 10 min and it wouldn't idle. When it shut off after that i jumped it again and it stayed on this time. The idle bounced between 400 and 1000 RPM but it stayed on. Now we get to the questions. First, should 10.92V be enough to start the car. I understand that this kinda depends on the amps it can put out, but what do you think. Second, I kinda think something is wrong with my battery. It has 600 CCA, and when i look online all the suggested batteries are like 750. Is 600 enough? And do you think that it sounds like the battery or something else?
thanks for any help.

 

You need to replace your battery. At 10.9V, it's telling you it can't hold a charge anymore. The battery should have about 14V for it to be healthy. Also, the PCM and electronic controls require a healthy voltage for them to function correctly. Go get a new Interstate battery that is specified for your model truck. Also, make sure your battery cables are in good condition--no quick-fix temporary battery terminals. Replace your cables if they are in poor condition. After that, you should be good to go.

 

yeah ^ all that.

your 10.something voltage test was with no load. if you had 4 arms and could measure the voltage while also turning the key to start, you'd probably see it fall way down. once it starts, the alternator is pumping out the 14 volts, but like said, the pcm doesn't seem to work off the alternator only, although it seems like it should, and i don't know why it doesn't.