Will not turn over I need help

vehicle overheated stopped made a quick fix on radiator and refilled with antifreeze started everything seemed ok drove car home still everything was fine next day will not start. turn key to on position lights on dash and headlights good, turn key to start position all goes dead. fuses are good battery is good connections to starter are good engine not seized up. I get no code on my odbII. I have replaced radiator and hoses, checked alln fuses in all four fuse box and side compartments. I need help

Help us help you then. First, its really hard to follow someone who doesn’t type in full sentences, and who uses shorthand for things like “battery is good” and “connections to starter are good.” I don’t know you, so I don’t know why you think the battery is good. Did you put a volt meter on it? Did you put a volt meter on it and watch while you turned the key? Or did you take it someplace and have it load tested and the CCA checked? How about the starter connections? What do you do to check those? Stuff like that. It’s the internet. Abbreviated short hand just makes for confusion.

What I would really need clarified first is this: “turn key to on position lights on dash and headlights good, turn key to start position all goes dead.” When you say “all goes dead” do you mean all the dash lights turn back off? And the headlights? I’d be thinking about a bad ignition switch or internal battery fault. Without more info I don’t think I could speculate on any connection to overheating & the radiator. That sounds coincidental.

Well can you explain better. You have written that when you turn key to start position all goes dead. Do you mean that when you start nothing happens/dead, or is the car trying to start/cranking and not starting. What model/year??

You don’t say what year this Impala is, but it probably has side mount battery cables.

Remove both cables from the battery. On the positive cable peel back the red cover to expose the positive terminals to the battery. If a lot of corrosion is found on the terminals under this red cover replace the positive battery cable assembly.

Tester

I think the engine is seized, How do you know it is not?

What voltage does the battery measure during attempted cranking?

Sorry I did not put vehicle details it is a 2002 chevrolet impala 3.4L engine. Sorry I said all goes dead after turning key from run to start but in start all lights are off. Sorry I wrote in what you think is shorthand but most places only allow you to type so many words and please excuse me if I miss type words because I am not perfect and this problem is just shy from making me go broke and the dang mechanics everywhere else I have paid for measly attempts just gets me no where (to include the Dealers). Glad to see we have a bunch of mechanics out there that are willing to help. Rule number one check battery connection corrosion breaks in wire bare wires make sure all connections are tight and when dealing with a customer recheck cause they did not. I am a 25 year war vet retired so if i sound a little short that is because I am disabled and cannot afford anything anymore.

Ok so I will try again: Just because i said it overheated and I replaced the radiator is because that is what happened the day before it would not start. when I say all dead What I mean is every light goes out once I turn the key from the run to start position and I do mean all the lights (headlights, dash lights,rear view mirror lights and all interior lights} battery voltage prior to starting 12.8 volts when attempting to start 12.8 oops 12.8 VDC vehicle does not turn over or attempt to start when i check the fuses with a multimeter they all test good or should i say none are blown. the reason I know that the engine is not seized is because i got my trusty little wrench and socket and turned the crank so that i could check the compression on the cylinders. I hope that is better

First,

Thank you for serving for our country.

Now. Did you actually peel back the red cover for the positive battery cable assembly?

Tester

yes i did sorry i did not say that and there was no corrosion

I also thank you for your service.

This is acting like a bad ground or a bad ignition switch.

so where do I go from here then point and I will check.

How old is the battery?

Tester

Its the ignition switch. See here:

ok ignition switch on the way will post if that does not work.

Did you ever just check for 12V at the starter S terminal while an assistant turns the key to Start? For that matter you may as well jumper the S terminal with 12V to make sure the starter operates.

And just to be sure, did you actually remove both ends of each battery cables - both pos and neg - clean the terminals completely and re-tighten them?

What about the possibility of a poor connection at the battery positive cable junction terminal?
All power except the starter motor windings go through that terminal and a poor connection can occur at any time. That could lead to a no-start condition and a VOM showing 12.8 volts at the battery.

With any kind of current draw by anything that battery voltage should drop from 12.8 down to whatever all depending.

Here is a schematic. Show a relay, starter and of course the ignition key.

Ok you have a faulty ignition switch. Sorry I asked to explain better because I wanted to make sure if its the engine or something else. For common problems, preventive maintenance, and recalls check this site out:

For ignition switch info check this out:

If possible, I would run a hot wire from the battery positive terminal to the positive (large) terminal on the starter. Hook to the starter first. (I say “if possible” because it may be hard to reach this terminal on the starter. Be sure the car is not in gear. Do not insert the key for this test since this test bypasses the key and the starter solenoid. This would at least test the starter to see if it works and we can go from there.