I recently replaced the alternator (91 NX2000) with a used Nissan one and everything seemed fine. Driving home tonight I began to open it up in third and the battery light started to come on. I backed off and it immediately went off. It starts to come on only with full (or near-full) throttle after about 4000 rpms. Just the battery light. Is this alternator on its way out too? Are the idiot lights coming soon.

why don't you check the battery?

change your battery. usually when your battery and parking break ligh comes on its your alty...

I've had it turn out to be the battery more times then I've had it turn out to be the alty. If a battery has a shorted cell, it will read 12.6 volts, but the second you put any load on it, it drops down to like 8, and the brake and batt. light can come on. Change your battery

just sell me your car, wait your in Canada, i don't want a rust bucket

I changed my mind, just put a piece of electrical tape over the gauge cluster where the lights are.

Thanks guys, I'll check the battery again. It checked out fine after the new alternator. I hope it's just the battery. And yes, I have a rust bucket, but I love it.