94 S-10 Blazer Starting/Power Problem

ok heres whats happening with my S-10 Blazer 4.3L 4x4...when my truck sits there for about a day i open the door and the lights are dim...i go to turn the ignition over and it cant get enough power to do it smoothly, it's kinda like the starter is sticking and cant go but i dunno thats why im here...once it does turn over and usually it does the engine revs really high for a second then goes to normal then the interior lights are bright like normal...i have just replaced the fuel pump and filter about 3 days ago...i have changed the battery, and the starter a few months ago and i got them and the alternator tested at checker and they said it was fine...i'm stumped on this and so is everyone else that i've talked to...i had some issues with once i changed my spark plugs about 5 months ago that my cruise control, vents and 4 wheel didn't work...i looked forever to figure it out and i couldn't but then i say a vacum line by the distrib cap and connected it now all 3 work fine but i'm still having the starting problems with it and am getting very irritated, its like theres a power drain somewhere when the trucks off and i cant think of anything so please help me!!!!

ty

I would say the alternator...Testing isn't always reliable... Also the tester itself isn't always reliable... It's either that or you have a draw in the system that is draining the battery and making the battery too weak to turn the starter.,.

Howdy, welcome to the forum. Before any of the real gurus ask, are your battery cables clean? If not, it could cause the problem you are having. Get a battery post cleaning tool and make sure the cables and posts are good and clean then see what happens. Good luck. :2cents:

i've cleaned the terminals, the connector and everything for the battery, i'm still stumped on what it could be...is there anyway to test it somehow to figure out where there could be a draw in the system
i know that there's been a problem with my rear defrost...its not hooked up in the back and the switch is kinda funky...it seems that once i got it fixed and hooked up this problem happened...could it possibly be the switch...

It is the alternator for sure, it might not be completely dead, but it is weak.

The engine is overrevving because the engine notices the low alternator output and is adjust ing the idle to get the voltage up to par.

Replace the alternator soon or you will kill you battery again.

Make sure you charge you battery back up before you install it with the new alternator.

i just changed my alternator and it is still having the problem...any one else know what it may be?

could be the voltage regulator

anyway to test that?

im not sure, go to autozone and ask them they should know