hello, i am a new user. i am joining because i have been having a very strange issue that i have no idea how to solve. my truck is a 2003 silverado, 2 wheel drive, regular cab 4.3 liter.
the problem is that when i turn the key the battery seems to be dead. lights on the cluster go out. engine fails to turn over but sometimes the engine will start and its like it is not getting enough rpm, if i do nothing the engine will seem to warm up and then be fine, or it will continue to loose rpm and die.
i have tested the battery and it checks, i replaced the starter less than a year ago and at the same time i replaced the main power cable that comes off the battery and goes to the starter. Any help is greatly appreciated!

 

Check the ground cable at the battery at both ends for looseness or corrosion. Not just at the battery, but at the other end as well.

 

I checked both sides of the cable and everything looks clean and tight. any other ideas?
thanks