starting electrical problems :(

[draggin2000]

I picked up a 94 mx3 1.6 5spd the other day for $500. it's beat up and kind of rugged, but with some tlc i hope she will be nice enough to turn heads. but before i do that i'm having a problem, something that is so beyond me i'm at a complete loss. i picked it up drove it home about 15 miles home, cranked good and ran good all the way till about a mile from my house. then it started idling really weird from about 800 to about 1500-2000 in short, consistent revvings. i got her home then checked her all out found a shitload of leaks i have to fix and other things. the next day it wouldn't crank. just to be safe ripped everything apart cleaned all terminals, made sure the main wires had good continuity, brought the starter, alt, and battery had them all checked at 2 different places, everything was good, put her together cranked up fine about 10 times. then nothing. used a multimeter to check the alternater while running, charged the battery fully, and put in a new starter to make me feel better and blow money. nothing on battery sat at 12.88, when cranked up it went down to 12.20ish and kinda just dwindled away, problem solved so i went and got a new alt. put that in then tested off:12.89 on:13.5+ sweet. well i took it for a ride tonight to see, and the charge light came on, and the idle is back, is there something i'm missing? i know some cars have a fuse between the exiter wire and battery, but i cant find anything. any help would be appreciated.

[Nd4SpdSe]

Something is a miss. There is a fuse, not sure the size, but it'll be the largest one in the engine bay, usually around 80amp, and may be bolted down. If the fuse is blown, you don't be getting any power in that circuit.

One thing I could check, start the car, disconnect the battery completely, and check to see if the alternator is still pumping out 14v.

I want to suspect a lose or bad ground on the alternator end

[Daninski]

Big thing is corrosion with our cars. Pull back the protective rubber shrouds at the terminals and check. Corrosion on the wires can kill electron flow.

[draggin2000]

thanks alot guys i'm still fighting this like no ones business.