The battery in my son's 91 Maxima died yesterday. I threw a spare battery in it on the side of the road and it cranked up just fine. I didn't have a voltmeter with me, but the charge light was out, so I figured it was charging. Well the spare went dead today, and luckily I charged the other battery last night and was able to swap it out again and get him going. This time I put a meter on it and it's not charging. The wierd thing is that the battery light comes on when you turn the key on, but goes out when you start the engine. I looked at a schematic in my 87 factory manual, but I'm not sure if it's exactly the same as the 91. We just got the car two weeks ago, so I don't have a factory manual for it yet. Does anyone have a 1991 factory manual that you could scan the charging system schematic page and e-mail it to me PLEASE? I don't need to drive it tomorrow, so I plan to check it out when I get home from work. I'm not sure why the battery light isn't indicating a problem. I have a spare alternator I can put in it from the 87 we have, but I'm curious about the light. Thanks in advance if you can help me with the schematic or if you any advice on this problem.

Kelly Finn
pkfinn@bellsouth.net

 

http://www.cybrrpartspro.com/Chilton.../82613w01L.gif

here you go

got it from chiltons online website
http://www.cybrrpartspro.com/chilton...oot/index.html
and looked up 1991 maxima

engine and engine overhaul -> engine electrical -> alternator

 

I saw a link to the Chiltons online once before, but when I went to it, none of the images would display. There were just a lot of little boxes with red x's in them. It works fine now though. I bookmarked it for next time too. Thanks again. If anyone has experienced an inop alternator WITHOUT a warning light, I'd like to hear about it.

 

Maybe the alt in your son's car charging enough to keep the light off, but not enough to keep the battery charge. Let's say about 13.0v maybe. When you do get a volt meter on there, see what the charging volts are at 1500 rpm with no load (all lights, acessories, etc. off) and with a load (turn on anything possible) Just sounds like your alt on the way out.

 

Yeah, the battery was reading 12.5v before starting, then dropped to about 11.0v during starting, the read 12.25v with the engine running. I'm hoping all that's wrong is the alternator is bad. I checked for battery voltage at terminal B on the alternator with the engine off. From looking at the schematic, the fusible link in the circuit must be okay. I'll ley you know what happens after I put another alternator in it today.

 

Well, this story has a happy ending. I put the good alternator off of my 87(which is awaiting repairs after a timing belt incident), and it now works fine. I'm still baffled as to why the charge warning light didn't come on if the old one wasn't charging, but I guess you learn something new every day. Thanks for your advice everyone.