SimbaDogg

I was having issues starting my car, I figured the battery was old (4 years old), ran a test, it was putting out 12.1v

So I decided to get a new battery under warranty at autozone, put it in car and it still won't start.

The weird thing is, if I hook up my ravpower portable jumpstart battery pack, it starts and turns over without an issue whatsoever.

I've checked terminals, chassis ground (right behind battery) and can't think of what would be causing this.

Any ideas? BTW I tested the output of alternator, and it's putting out around 14.3-14.4 which is within spec

Additional info:
- when I try to start car on regular battery power it makes a single click, doesn't make repeated fast clicks
- the starter doesn't turn over at all

flanders

Did you check the voltage of the new battery?
Check for bad connections on the battery terminals?

SimbaDogg

Yes, voltage on new battery is fine. Terminals are fine and totally clean

cosmomiller

If you add a battery pack and the car starts fine, the problem lies in the battery power. Either that “new” battery was discharged or it is defective. (It happens)
Charge the new battery fully and then try.

NNY S2k

^^^
Levi

SimbaDogg

It's not the battery.

I didn't mention this, but took the battery out of my dad's tacoma after the new battery failed to work....it still doesn't start

Same click, but doesn't start

flanders

How are you connecting the jump starter, right on the battery terminals or the negative clamp somewhere else on the chassis?

SimbaDogg

Right on the terminals.

​​​​​​I was thinking it was a bad ground somewhere, but the portable battery pack cables aren't long enough to reach any other grounding point

flanders

Alright so the only thing you are bypassing is the battery and the connection between your battery and the terminals.
So either one of them (or both) is the problem, based on your information
Next test might be to measure the voltage at the battery as you are trying to start the car, how much does the voltage drop?

jackmugen02

Don't use jumper packs on the S2000, it will damage the rectifier and you will get a flickering gauge cluster. Billman told me this and I had to replace a rectifier($200+ part and labor) to fix the issue I had on my very low mileage S2000. I jumped it a lot. Their is a alternator company that is selling rectifiers for $30 on eBay too.