Truck dead, starter click - Battery is Good

[nimrod.sixty9]

Thanks for all the help guys.
Pulled a battery from our dead Firebird and it worked, worked with way less charge than the original battery.
Old battery still tests good, so I dont know what to think about it.
Im still going to probably have to get another battery as it still seems like it a has a weak start.

 

[PNWYukon]

Are you saying it was perfectly fine before you changed the oil and then suddenly it will not even crank?

Turning the key to the on position leads everything to fade out from lack of electricity?

Is your vehicle rusted out?

If you have corrosion on your battery terminals, then that is your problem.

Grounds.

 

[nimrod.sixty9]

Are you saying it was perfectly fine before you changed the oil and then suddenly it will not even crank?

Turning the key to the on position leads everything to fade out from lack of electricity?

Is your vehicle rusted out?

If you have corrosion on your battery terminals, then that is your problem.

Grounds.

Very clean Florida truck, but I did clean some grounds that were indeed dirty.
Still I want to find the ground for the main negative lead.
As some one mentioned before was to check for corrosion and did.

Its starting now with the Firebird battery. Still weak tho.

 

[PNWYukon]

Looks like it is G105 for you battery.

 

[drakon543]

so you op also mentioned a triple start bump to prime the oil. did it stop before that or after that? starters heat up when they are being used. the hotter they get the harder it will be to start and a high amo draw. so if you bumped it 3 times in a row you could have heatrd it up and if it was getting close to failing already would be the case. also if both batteries are reading 12.3+ the original one could either just have a lower cranking amp rating vs the other one which is what helped it start. it could also be reading good but just be going bad anyway. proper voltage but a reduced capacity will lower the cranking amps. ive actually had a starter fail this way before and took it to autozone to have it tested. it was pulling enough draw it tripped the stores main breaker.

 

[Yukon_]

So just changed oil, and now I cant get her to start.
In just a moments thought, I thought I would just bump the starter a couple times to prime the oil pump.
Sounds dumb in hindsight.
Third crank, the whole truck just died.
The interior lights dimmed, cluster was flashing, wipers came on, AC blower motor barely moved.
So put the charger on the battery, but it has enough juice.
Try the load tester, battery tests good... very good.
Leave it to charge overnight anyway and try again, same result, acts like battery is dead.
To clarify, I only have to turn the ignition to ON, not crank, for all the power to seem very weak.
Appreciate any help!

Check the negative power cable to battery. Mine had some hidden corrosion inside the cable jacket that was just enough to stop a solid connection I ended up having that cable replaced, and it was fine afterwards.