2000 chevy S10

wont start replaced battery,starter,key tumbler,clutch switch,relay and fuse in main box. turn key on guages all work, turn to start you get a thonk and the battery guage goes to 0, release to on,guage goes back up ? wont start with jump, atlernator is charging. the next day it starts, the next day it dosent. i need some help! lost rmh

Ignore the dash gage. The circuit may not even be enabled when the key is in START in order to allow all of the battery energy to go to the starter.

Do you have the meter and knowledge to check at the battery to see if it’s getting 12VDC when the key is in the START position? Checking for that can eliminate a lot of possibilities. If the motor has 12VDC and the crank isn’t turning over, than you can eliminate every possibility before the starter.

At that point, since it’s a new starter, I’d want to double check the installation for proper shimming, as an improperly installed starter may not properly engage with the flywheel reliably. That “thunk” you hear may just be the starter gear trying to engage with the flywheel ring gear.

If the starter isn’t engaging properly and it’s properly installed, you may want to inspect the flywheel’s ring gear for missing teeth. You may have to remove the starter and watch the gear while a friend turns the crank by hand (or turn it yourself with a ratchet on the crank bolt), but that would be your next step.

Post back with what you find out.

@rmh

Check out the starter and battery cables very carefully

Make sure everything is clean and tight

Those side terminal battery cables often hide corrosion under the plastic sheathing

If you’re at all in doubt about the battery bolts, replace them. They’re readily available. I’m talking about these things

http://www.oreillyauto.com/site/c/detail/SS01/01337/N0365.oap?ck=Search_N0365_1361506_3210&pt=N0365&ppt=C0061