I have a 2008 Silverado that will start fine for a week and then won't start. When i jump it, it takes less than a minute to start. Today i drove it to work today about fifteen minutes. Shut it off move it about a hour later started fine. Tried a few hours later and nothing, interior lights work, there is a what sounds like a hiss from under the dash.
I jump it, starts fine. There seems to be no other electrical issues. The battery is almost 3 years old. When i put my meter on it i get 12.3 volts and when running i get around 14.8 volts. Last week it sat for a day with using it and i had to jump it the next morning. Connections are clean and tight.
Thanks for any help.

 

It really sounds like a simple battery problem to me. Your alternator appears to be putting out power to the battery, so my guess is a fading battery, or mayhaps some corrosion issue.

 

Thanks for info. It has started fine for the last week. I am wondering if it may be a ignition switch issue as it is so intermittent
Thank you.

 

My pleasure. It is possible its the ignition switch, but you might want to have the battery checked out. Many are made in Asian, and quality control is no as good as North America.

 

It's not so much a factory quality control issue as it is a GM cutting corners issue.

My Delco battery dated 2017 has a manufacturer plant code 'R'. Anybody know what that is?

 

Not sure that it is the battery. It seems that if i go in and out of the passenger doors that is when it won't start after a couple of hours. If i don"t use that door then it starts with no problem. Does anybody have any input?
Thanks.

 

you might have a short in the door harness. try taking the boot off.