Nissan Repair: ´96 Maxima fighting the startup

Question
QUESTION: Hey Von, thanks for your time and expertice. I have a 1996 Nissan Maxima GLE (I believe), with 150.000 miles. It was wrecked before and repaired. Runs great except for one little thing - for the last 7 months I have been having problems with the starting. The lights and horn work, it will turn over - but not turn on, if you do this enough times, it will do it slower and slower until I imagine the batery just has no more juice left and it just "clicks". I changed the batery with one of Wal-Mart´s finest - and a month later it was still doing it. I had to get jumps and actually leave the cables on for several minutes in order to overcharge the system and get it to turn on, I would even get in and shut the door quickly so the interior lights wouldn´t drain it and I´d have a better chance of starting. I thought it may have started a few weeks after I installed an alarm system, so I had the alarm disconnected, - it was still happening. I asked about the alternator or the cable connecting the batery to it (although the car has never shut of on me while driving) - I´ve also been told they are fine by several mechanics. I had the starter checked and finally replaced by a Nissan mechanic friend and he told me it had a crac on the celunoid and it had not been making contact. Afterwards it´s been good for a month and a half. Finally every morning this week it has been turning over with less and less "strength" than the morning before and I knew the inevitable was comming. Finally this morning - it turned over but would not start. Should I do a tune up (dirty spark plug ?). I like the car so I don´t just wanna put a bullet in her, but I don´t have the money to do and entire electrical system replacement. I also don´t think that any Mech wants to take the time to go over all the electrical system to see if any part is touching something and grounding the charge. Wal-Mart won´t give me another batery (in case it was a bad one) unless I bring in a print-out from an autoparts store or somewhere that says "The batery is bad". I explained that when turning the car on the voltage drops from 12-13 to like 7-8. I don´t think it´s suposed to be that much - but I don´t know. I´ve been to 7 different Mechanics and no one seems to know, some say battery, I feel like sitting on the ground and waiting for the rest of the Ten Plagues to come but I can´t give up just yet. I am paying my way through Med School so I study in Mexico ( it´s cheaper), and will be back in the states in a few weeks,  Nissan In Texas won´t take a look at a Maxima this age - what should I do.

Riding a Bike ang getting used to the work out.



ANSWER: Hi Keith -

BTW, this is Calvin, not Von (hehe)

We need to do this by process of elimiination. If one cannot find out what it is, lets find out what it isn't. First and most obvious, I want to check the battery, because from what you describe, seems to be the culprit.

Take a digital voltage meter and measure the voltage of the battery:

12.9 is a full charge ready to go
12.6 is average
12.3 and below is undercharged and needs to be brought up to 12.9

Once the battery is fully charged, leave the voltmeter on and turn the lights on. Voltage should not drop below 12.3. Start the car at the same time the lights are on. If the voltage drops down way low, then the battery is not good.

Please do this check and get back to me.

Thanks
and aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: Hey big Cal,

Sorry about the name mixup. This is the guy witht the ´96 Maxima that wouldn´t start. Just wanted to say thanx for answering and wanted to let you know, I plan on going to the states this weekend (from Mexico) and I could get a new battery, but before that, I noticed that the last time the car would turn over but wouldn´t start (a couple weeks ago) the lights and horn were still working. I let the car sit alone and yesterday when I went back I noticed it was COMPLETELY dead. So why did it go from undercharged to no charge. This leads me to think it may actually be something to do with a short or contact in the car that is draining the battery while the car is off - like the ignition that is loose or touching and dropping the charge while I am away. I have checked everything else several times. Or what about the brushes in the regulator in the alternator. I don´t know, I´m just wondering if it´s something else other than the battery cause I´ve changed it not too long ago.

Your thoughts.

Thanks,
Keith  

Answer
Keith -

Assuming that the battery is good and not dropping its charge, there is a way you can check for battery drain, however you would need a digital ammeter that measures milliamps. Do you have access to one?

If so, do the following:

Remove the negative battery cable and place the ammeter probes, one on the disconnected battery post, and one on the disconnected terminal. If you read more than 30 milliamps, then you have a battery drain, and would need to remove and replace the fuses one by one until you get a zero reading. You have then found your short. Keep in mind that you might have to pause a few seconds after pulling out fuses, as the computer has to "close down" its circuits. Until then, you will get amp readings.

Hope this helps -
aloha
calvin