Alright my car has been down for about 2 months with an electrical demon. For some reason the alternator isn't charging the battery. I swapped out the alternator... same problem, i had my battery tested, passed, my roomie ran it in his sr20det for 3 weeks with no problems. So battery and alternator are good. The fuse on the battery terminal blew and i re-soldered it and that's the only thing i can think of that, i swapped to a ported intake manifold and throttle body, and in the process i checked all the wiring from the alternator to the battery... and all the wires seemed to be in ok shape.

When i crank the car, at idle its fine, but when given gas, the battery and the e-brake light come on. And then the lights start to dim, and the battery dies.

What would cause the battery and the e-brake light to come on at once? there's clearly a short somewhere and all the fuses are fine. I'm going to test my AEM EMS which SHOULD be fine, but i'm going to try my stock ecu tomorrow and see if the same problem occurs, i suspect it will.

Any suggestions on where to trouble shoot first? I'm gonna take out the volt meter and test the wires from the alt. to the battery tomorrow also.

 

Sounds like an open circuit to me.

Alternators aren't actually generators in the typical fashion. They have no permanent magnets to make them produce power. Instead they use a "Stator" coil which is run by the battery. By regulating the voltage to this "stator coil" we can produce a positive increase in voltage or no voltage at all. This is essentially how an alternator works.

My guess since you fried fuses is the stator coil isn't getting much/any power. I can assume a few reasons for that.

1) Voltage regulator unit is dead and not providing power
2) Ground to stator circuit is open
3) Fusible link in stator coil to positive battery terminal is broken

BTW the circuit looks like this:

 

id bet its one of the wires from the bat to the alt...i dont think its the alt cuz he said he used a different one and its unlikely that the other one is doin the same

 

yeah i put a brand spankin new $310 dollar alternator in a month ago. after all this started happeneing

 

actually that diagram helps out a LOT, just cause the alternator isn't working doesn't me the wiring isn't bad, and that diagram is perfect thank you so much RoadSpike!

 

bump, i don't think that diagram is evo specific, i just pulled my wires and they don't run like that =[

 

I went thru 3 alternators, same lights came on with my dash. You have a bad alternator that thing inside maybe? Someone will know what that "thing"is. You are as cursed as me.

Did you change cams/timing belt lately? did you check the bolts to EVERYTHING running off the serpintine belt? Do you get excessive vibrations at 4-4,50rpm? have you ever shredded a serpintine belt? REcent MODS? You have the same problem I HAVE HAD!!! I know what helped me, just need to know more about your situation.