ok heres the deal this question is actually for my beater 87 accord, but i figure its the same.. or close.

when i got the car the battery light was on and had all the tell tale signs of a bad alternator. so i replaced the alternator(u think its bad on a crx? try it on an 87 accord!)
anyways, when i replaced it i noticed that the main wire that goes to the battery was corroded, so i found where the wire ended up and ran the same kind of wire off a gsr harness i had laying around. once replaced the battery light went off, but the car still needed to be jump started. once it was jumped it ran ok, i say ok because i had never driven the car b4 but it seemed fine. frustrated i bought a new battery. once the new battery was in everything seemed fine. once week later the battery light comes on and shortly after the car dies. now if i jump it as soon as the cables come off the car revs high and then dies. i put a tester on it and once the cables are pulled off the car revs and the power coming through that wire i replaced starts to decrease until the car dies shortly after.
besides the alternator being bad, cuz i just got the thing, what else could it be? i am guessing the other suggestion people might have is to check the connections... i have sorta half heartedly checked them. does anyone know if that main wire, off the alternator that goes to the bat, is supposed to connect to anything else on its way to the battery? when i checked it out it seemed to just be going from the alt to the bat.

thanks for any ideas

-tired as heck i hope this reads ok...

 

Having gone through similar issues I have a few things to recommend.

What alternator did you replace the original alternator with? Was it new/used? What car did it come from? How do you know that alternator is not bad too?

Check alt belt tension and check your grounds.

Once the engine is started you should be able to pull the battery out of the system and the alternator should provide enough power to support the system. So your battery is not the problem.

Id try another alternator

 

whatever you do do not run the car with out a battery connected this will cause voltage regulator to believe that the battery is dead, putting alternator into overdrive basssically, 100% output and more than likely fry your pcm if your not lucky...

 

the tension on the belt is tight, the alternator is from autozone its "new" and under warrantee. i was just hoping it was something else b4 i went taking it out again. u have to drop the axle to get the stupid thing out and its getting cold out side quick...

 

On my 86 Accord you could take the Master Cylinder loose from the booster and wiggle the alternator out from the top. It is a pain in the *** but still easier than taking the half shaft out.

 

yea, it's the same with CRX's w/ B16s. You just need to take out the master cylinder. It's a whole lot easier then pulling the axle out. Spent a long time figuring out the best way to get that pos out.

It also saves you the hassle of taking the mount off the block (if you have to with the accord... not sure if you do)

And as for your problem my guess would be your alternator is bad. You seem to know your **** so the alternator is more than likely the problem. Just go through the troubleshooting steps. Check all fuses, then all the wiring and grounds, belt tension, etc.

The nub on the top of the alternator (not the o-ring harness the other one that the "top-hat" connecter goes onto) can become loose sometimes. Make sure it's not loose.

 

Go buy a cheap voltmeter. You can get one for $10. I recommend a digital multimeter, though. You can get one for about $35. Take voltages at the battery with the car running and with it off and let us know what you get. Its kinda pointless troubleshooting without a meter.

 

Yea id definately replace all the grounds. I had a similar problem a few weeks back and it ended up being a ground. The bad part was that you couldnt tell that the ground was bad...it looked fine. But as soon as i replaced it that car started.

Also check the hotwire from your alternator to the fuse box(i assume its like that on the accords too?)...not just the connections but the whole thing. It coulda rubbed up against something and grounded out maybe? Or the wrap mighta came off and the wiring got corroded.

Does the rest of the car have power...or is everything dead? Good luck

 

everything is dead

thanks for all the tips now i just need to crawl out in the cold...