My 85 s10 blazer wont start up at all. battery is good. brand new and tested good. changed the terminal posts also. the lights and everything turn on but when i try to start it, it dont even click or anything at all and makes no noise when attempting to start it. how can i get it to start? could it be the starter? if not then what else could be the problem?

You need to do an OBD1 fault code test on the engine control module. You can do this test and read the codes by following the instructions at the link provided. FAQ How to read older GM codes for free

The power cable from the alternator is not connected to the red battery cable right male shire. The cables alright from the terminal on driver side terminal just in front of hold hinge. Thick black wire should go to cable positive and have power 12 volts even wen motors off as when rite connection it's to positive Post (bolt side post)on battery. Had this problem myself it had a ring with wire but it set on battery sideways wasn't connected rite so I put wire (alyonator) on the aftermarket lead clamp that fixed it could charge cause it connected then hope this helps

have the battery load tested as brand new batteries can be faulty. Check that the terminals on the battery are shiny clean and tight. Check battery leads are in good condition and not corroded away and check the earth wire is fixed and in good condition.

If you have a test light, what you want to do it to disconnect the negative terminal from the battery. Connect the test light between the negative post on the battery and the negative cable. Be sure your doors are closed and the hood switch if you have one isn't on. If you are showing the light lit, then you have a draw. To isolate the circuit you pull one fuse at a time and replace it until the light goes out. That way you have isolated the circuit that's causing the drain. from there just start tracing wires.

think your starter motor is no good or the battery is flat ,try charging the battery for a couple of days as well

Sounds like you have a bad spot on the starter armateur...and will need to replace the starter.

If its the original, and you have over 50K miles then its probably a safe bet that your starter is bad, and will fail totally soon...if thats not the case now.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

begine with a test of the motor first,do this with a test light,under the glove box is your blower motor,turn the key on and heater fan and defrost,now ground the test light to a good ground and test the wires to motor,if you have power replace the motor.

You need to begin testing at the battery using a volt meter. Power requirement of interior is far lower than the starter needs. Check battery for 12v, check that posts & terminals are clean and secure, Check starter relay in the power distribution center, make sure grounds are good at the engine end. Check for 12v at the starter main terminal and 12v at the starter trigger wire with the key in the start position. (if you have both, likely starter has failed,) if power only at main terminal, re-check relay, and also test neutral safety switch and ignition switch.If no power at main terminal go back to the battery and re-test everything between again.

check your battery terminals clean them and put back on, if by small chance that isnt it check for a fuseable link ,follow battery wites make shure both are tight and clean on both ends

Its most likely the voltage regulator which is most often attached or inside the alternator its a replacable item. Normaly the sighns of an alternator gone are a dying battery.