Car isnt starting! Help!

[neogen69]

I just checked my battery at Autozone,and they said it was fine.
IT started last night, i was driving with the casette player on, and all the lights came up (e brake, Engine, etc.)
Then i parked my car at myfreinds house, and the car wouldnt start, so i got jumped, and it was running. I drove it again, and i had the lights on, and the car starting blinking again, and i felt the car shaking because it was on the edge of turning off.
So the second time i got jumped, i let it sit for a while (30 minutes)
and when i turned my headlights on, the engine stopped.
now, when i turn the ignition,i dont even hear a sound, as if it's trying to start.
It's definately not the battery.
If someone come help me, i'd appreciate it very much.
Thanks.

 

[CRE]

Test the alternator, check all the fuses, check the wiring to the alternator and battery.

 

[supramacist]

Ya that was my first thought cre. But if you think about it, the alternator being out would drain the battery to not even clicking the starter. Not that your'e wrong dude by any means because that is where I would be looking.

I wonder when the last time you have changed any of those wires out would have been. Because all the wires to the afore stated parts get crudded up inside and coat themselves and stop conducting all together.

It sounds electrical for sure.

 

[CRE]

I mention the alternator, simply because I've done it... run with it unplugged I mean... lol. I freaked. :runaway: Then felt like an idiot. :squint: Anyway, my car acted alot like what neogen69 described.

There are a number of possibilities, bad voltage regulator, alternator putting out juice, but not enough, a bad ground. It really sounds like something in the charging system to me.

When you had the battery tested, was it depleted?

 

[cuel]

The easiest way to check the alternator is to start the car with a FULLY CHARGED battery, and then check the voltage at the battery terminals with a volt meter. The alternator should be putting out 14 to 14.5 volts. If your getting 13.5 or less, check it again on the alternator itself. If your getting 14v+ there, and not at the batt., try cleaning the terminals, or change the cable. If your getting 13.5 or less at the alternator, replace it. If your getting a reading of 15 volts or higher, the regulator is bad in the alternator, and you need to get a new one(alternator). The alternator does double duty in an automobile. It charges the battery, to replace the energy used to start the car, while, at the same time, supplying the necessary voltage required to run all of the electronics in the car while its running. Once a car is started, you can, technically, take the battery out and still drive it around with all of the accessories on(this is NOT recommended). Just don't shut it off... The battery's main purpose is to supply electricity to the starter when you start the car. Secondary is to supply power to the electronics when the key is in the on or acc. position while the engine is off.
Make sure your battery is fully charged (should read 12.5 to 13.5 volts steadily) when you get the new alternator in. If you just jump it off, and run the car with a dead battery, you'll put to much stress on the alternator, and prematurely wear it out.

 

[supramacist]

So charge the battery before making the alternator earn it's keep.

Sinse wer'e talking battery I have a quick q. Can I with the wiring harness detached, plug up the battery and close my windows.

Sorry, and thanks.

 

[cuel]

Hmmm... not really sure. It would be possible to operate them with a jump box. Hook the ground to a clean bolt head. I usually hook a ground to one of the 2 big(17mm?) bolt heads on the bottom of the column down by the fire wall. Useing a jumper wire, hook the positive side to the blue(not blue w/black stripe) wire going to the master switch(drivers side) from the main harness that comes through the door. This should enable you to roll up the windows. This bypasses the fuse and relay, so I wouldn't do it more than once if I didn't have to.
http://cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=094
This is the wiring for the power windows according to the tsrm.

 

[Junior]

clean your battery terminals dude.

 

[supramacist]

LOL.

That too.

 

[neogen69]

well i got it starting, but it's still have some problem
all the lights are still on.

 

[cuel]

Have you checked the alternator as described in earlier posts?

 

[supramacist]

LOL all of those lights mean that you are clear for take off. Go get the voltmeter neo. Track it down dude. There's nothing more to really say until you respond with......, ok I did that, what now.

It's odd. Start checking your fuse box and everything. Atleast eliminate the inside of the auto.

 

[CRE]

Let's not forget the current aspect of the alternator's output. You can still see 14.5v across the rails with an alternator that is providing the proper voltage but not enough current when taxed. I really don't know how the regulators used in our car are designed, but when the power input drops one or the other (voltage or current) will take a hit.

If you're testing voltage across the terminals of the battery while the car is running, at least load the system down. Turn on the headlights and fogs, run the rear window defroster... that'll tell you more.

Bench testing is still more accurate.

 

[Nick M]

He doesn't need to do a bench test. If has battery is good but discharged, voltage will be lower and amperes will be higher. If the battery is bad, the voltage will go high, known as full fielding.

If he has an alternator problem, he won't have adequate output period.

edit: yeah, you won't have a good output without a good field first

 

[jetjock]

Cuel has it right for voltage testing though it's tough to test an alternator completely without getting an ammeter involved. For voltage testing the battery should be fully charged and alternator output current below 10 amps. For current testing run the engine at 2500 rpm with loads applied. If the voltage doesn't drop more than 1 volt below standard (13.5 to 15.1) the system is working. If the battery is fully charged prior to current testing you should discharge it slightly by disconnecting fuel and spark and cranking the engine for several seconds.

*edit*: For more tech details see the SME Electrical Section.

 

[CRE]

Thanks for the info guys. I didn't understand how just testing across the terminals could be accurate. I'm familiar with the need to ground "F" on most alternators to execute a "full fielding" test. The seperate sense line seems like a well thought out addition too.

If you're in a situation where the battery's state of charge is unknown, I still don't see how this would be accurate. Nick, I understand that if the voltage of the charging battery is low the amperage usually goes high while the voltage goes low... To someone without much understanding of these systems (myself included) this could too easily lead to a false diagnosis.

I apologize for my ignorance in the finer details of this. I'm sure I must be missing something. Also, I'm not trying to cause anyone irritation by supplying inaccurate information.


EDIT: JetJock, that write up is very well written. I look forward to more!

 

[Nick M]

Thanks for the info guys. I didn't understand how just testing across the terminals could be accurate. I'm familiar with the need to ground "F" on most alternators to execute a "full fielding" test. The seperate sense line seems like a well thought out addition too.

If you're in a situation where the battery's state of charge is unknown, I still don't see how this would be accurate. Nick, I understand that if the voltage of the charging battery is low the amperage usually goes high while the voltage goes low... To someone without much understanding of these systems (myself included) this could too easily lead to a false diagnosis.

I apologize for my ignorance in the finer details of this. I'm sure I must be missing something. Also, I'm not trying to cause anyone irritation by supplying inaccurate information.


EDIT: JetJock, that write up is very well written. I look forward to more!

You have no need for apologies. I shouldn't have over simplified. All of your replies look pretty good to me.

As a non technical quick check, if the output is high, as in full fielded, 14.5v, there is a good chance your battery is FUBAR. The lead sulfate does not want to reverse itself, and the alternator is trying like hell to do it.

 

[cuel]

Lol, poor guys probably confused as hell now. By the symptoms described in the first post, its a bad alternator. 99% of the time, if the alternator's dead(not just weak), the only voltage reading you'll get from either the batt. or the alternator is whatever the battery voltage is. He unintentionally load tested it in the first post. He got a jump, let it idle for 30 mins., and turned on the headlights, killing the car. I just figured that with everything he described, that alternators toast, and the voltage test would be sufficient. As a matter of fact, if he connected a volt meter to it and watched it steadily for a few mins., the voltage would, more than likely, steadily drop as the running car drained the battery.

 

[CRE]

Sorry, yes, academics aside now. I concur. I too think it is most likely his alternator.

Neo, sorry for turning your thread into a technical discusison.

 

[jetjock]

Yeah, this went on for a bit didn't it. All he needed was to slap a voltmeter across the battery. Odd thing though. From what I see in the thread he never mentioned his charge light being on. What's up with that I wonder.

edit: now that I reread the thread he's got to have bigger problems than the alternator.