i have a 90 crx SI with a d16Z6 i ran a 0 gauge wire from the trunk to about the fire wall and ran wire a little thicker then oem from the starter and the fuse box to the 0 gauge wire and a 0 gauge ground with a battery from a 91 honda accord the car runs beautifully but after a while my battery light turns on. when i give it gas the light goes away now i thought maybe my battery wasn't holding a charge so i put that battery in my 91 accord but it had no such problems im guessing it could be my alternetor the one im using is from the original motor or maybe the 0 gauge wire is too thick or too long or maybe the wires from my fuse box and starter are too thin?? idk this is my first attempt to relocating my battery and im terrible with electrical stuff i was thinking maybe shorten the wires from the starter and the fuse box and get the 0 gauge into the engine bay? it sits about where my ecu is right now

 

This sounds like you are pulling too much current and you're alternator can't keep up with that draw at idle. Probably a sign your alternator is going bad or you are running too many electronics. Not 100% sure, just my two cents

 

why did you run such heavy wire? it's just overkill, you could have run 2 gauge just fine with that car, you did fuse the wire directly off of the battery right, I cant believe how many people dont fuse the battery and run a battery that outgasses inside of a car with no trunk. if the alternator light goes off at high RPM it's probably the alternator brushes

 

I dont mean to jump on your case, I hope your battery install is done right, but nearly every time I see an install on here, it's a plastic battery box inside of the car, with bungee cords, a conventional battery HAS to be in a sealed vented box, that is bolted to the body of the car, with at least heavy washers under the car, preferably a doubler plate, box needs to be metal, and it needs a maxi fuse or breaker as close to the battery as possible, conventional batteries do sometimes randomly explode, it happens more often then you think, if you get in a wreck, a battery held down with bungees is going to come flying at you, at whatever speed you were traveling. since you have a CRX, consider the battery inside the car, it's different in a trunk with a metal wall between you and the battery, if you need guidance, look at the rules concerning a battery inside of a race car, and what is required