heres my deal...i bought a 92 trans am ws6, it ran fine before it sat for a month (i had to sell my other car, parents rules )

i took apart my plenum/runners and polished them, put them back on....so it sat for a month, and then it wouldn't start. i jumped it and it started fine. ran fine too. i shut it off and it wouldn't restart.

i figured it was the battery, no dice. got a new one and it still won't start. when i jump it, i get about 13.5 volts running....then i was revving it would go down to like 13. i was driving around though and it was staying at 13.5, and the lights didn't dim or anything, even had the defroster on.

the guy who owned it before me said he changed starters or something and it would randomly not start sometimes. he said the starter wires are probably loose. does this seem likely? or do you think its the alt? any help would be great...thanks

 

I would disconnect the battery and check the wires at the starter, also check the battery wires for corrosion.

 

Inspect the connections at the starter solenoid and at the battery. Make sure they are all good, clean, and tight. Another thought could be the battery cables.

 

i have power though...interior lights and everything work with the engine off. voltage is usually like 12 though when the engine is off.

 

It's not the voltage that you need to look at here, it's the amperage draw that's being pulled when you try to crank..

 

can i use a multimeter to check this?

 

You can check the voltage, but most multimeters are not designed to measure anything more than 10 amps and even then it might blow the meter. What you can do is measure the voltage across the battery terminals as someone tries to start the car.

 

multimeter=fuses for dumbasses like me

 

to check amps, you need an amp meter.
you said you have a new battery, so getting the starter checked would be the next thing.
im not sure if auto-zone can do an amp test on the starter with it on the car or not, but they should be able to though as a starter can bench test good but still be bad under a load.

if the starter checks good but you still have problems. you can do this.
this will not test the battery or the starter.
you can use your multimeter to do what is called a voltage drop test.
you do NOT un-hook any wires, cables or other components to do this.

with the multimeter set to read DC volts, hook the ground lead of the multimeter on the ground post of the battery, then hook the positive lead of the multimeter to a good ground on the motor,
now watch the multimeter & turn the key to start, there should be no more than half (.50) a volt reading on the meter, any more & you have a ground problem between the battery & motor.
you do the same thing for the positive side except for you hook the positive lead of the meter to battery positive & the negative lead to the main terminal at the starter where the battery cable hooks to. hit the starter, again, anything more than .50 volt you have a problem.
what this test does is measure how much voltage drop you get through you cables. you can also use it to check most any other load items or switches you may be having a problem with such as headlight motors, fan motors, headlights, & so on.