95 J30 Won't hold a charge

[bororedsfan]

My son's 1995 J30 needed jumping to start today after work. After getting it started, it went a few blocks and began to skip and lurch and the ABS and AT lights came on. It then stalled. When I tried to crank it, once again there was absolutely no spark and it had to be jumped again. This happened four times until I was finally able to get it home. Any ideas? I am over an hour away from a dealer.

Thanks

[DAEDALUS]

Sounds like either an intermittent bad connection somewhere or the alternator needs replacing. The voltage with the car running should be above 13v. My money's on the alt.

[bororedsfan]

Please excuse my ignorance. I am not very mechanically inclined. WIll the alternator have to be replaced by an Infiniti dealer? How much should I expect to pay?

Thanks Again

[DAEDALUS]

Any shop with a good reputation should be able to tackle it. If you plan to keep the car for a while spend a bit more for a factory part. Our sponsors wholesale them for cheaper than your dealership. Call up Scottsdale at 1-888-216-5328. You'll need to send them the old one for the "core charge". Stay away from the Prostart brand--real junk. Make sure the shop you go to is OK with you brining them the part. The part will be around $250 probably, for OEM. Not sure about labor. Maybe 4 hours? The shop can give you a labor quote real quick from their labor book.

[bororedsfan]

Thanks for your help. I appreciate the quick response.

Dave

[Q451990]

Don't rule out the possibility that the battery is just bad. How old is it? Most parts stores will test it for you at no charge. That's where I'd start. Once you have the new battery in (if the old one is bad) check your voltage as Daedalus said. It should be about 12v with the car off and Between 13-14V at ilde with it running. I would avoid jumpstarting it again, as overtaxing the alternator with a bad battery can kill the alternator too. Some cars can run on just the alternator, but my experience is that most Nissans alternators are just barely adequate, and will not run the car if the battery is bad.

Heath

[DAEDALUS]

The battery could indeed be bad too and it's a good idea to change it every 2-3 years on principle. But the alt should have no problem supplying enough power at idle (especially with the lights off). Otherwise the battery wouldn't show over 13v at idle. The battery cells alone only provide about 12.6v when new. Only when the alt supplies too little power does the battery voltage drop below it's normal voltage.

[aaronl]

As said above car should run at idle on the alternator. Connect the jumper cables, start it, disconnect the jump cables, disconnect the battery. If it dies it is most likely a bad alternator. The alternator will put out more than enough power to run the car. If it didn't, the longer you drove the car the lower the battery charge would go until the car wouldn't run. The alternator powers the car and charges the battery when running. If the battery is bad it does stress the alternator in that it is using a lot more of its current capacity to charge the battery than if the battery is good. If the battery has a bad cell it can never charge to full capacity.

I don't know about the J, but be glad it isn't a Q if you try to change the alternator yourself.

aaronl

[Q451990]

My experience with failing batteries on Q1 on a couple of occasions is that a battery on the way out will cause driveability problems and the dash lights to flicker. Perhaps my batteries were failing in a way to create an additional drain - but that's my experience. That was over more than one OEM alternator too.

It seems like I remember a post from Q45Tech years ago (maybe even on yahoo) talking about how the car pulls more amperage at idle (especially with multiple accessories on (e.g. defrost, a/c on high, headlamps, etc.) at idle - and that the design relies on the battery to recharge at cruise and higher RPMs to make up for the losses at idle.

In any case, I would check the battery first.

Heath

[driverdriver]

Infiniti J30 alternator has been mentioned in a number of threads on this forum, I would strongly recommend that you get a Nissan OEM alternator and not any aftermarket version. Many J owners on this forum have had bad expereinces with non-oem alternators. For whatever reason aftermarket alternators have a very short life on the J. Also get a fresh new battery after the alternator is installed.

[Q45tech]

Non factory rebuilds are designed to last 12 months and 1 day [if they last a month or a week].............nothing but oem...... Bosch and other lesser remans are usually junk to say the least. Built to a price point that is not realistic to sell to national chains.

Factory remans can last 6 years or longer.

[Cdon851]

If you put 0.25 ohms across the field post to simulate a dead battery your alternator should put out as much as it can. All this is in the specs somewhere so I am guessing at the actual ohmage but the point is that if the field post sees a dead battery the alternator should put out.

The irony is that the alternator outputs nothing without the field being energized somewhat but if you put a full battery in then the alternator won't put maximum output. Your test changes the resutts.