Probably dead alternator

dwd1985 · #1 03-29-2006, 02:57 PM

Well I havent had a serious problem in the last 2 months or so, so I am overdue. and geuss what? I was right. I had just driven down to my part-time office which is about 70 miles south from my house. No problems on the trip down at all. I was only there maybe 5 minutes tops, and then as I was leaving, I came to a stop at a stoplight, and my CEL, ABS, and Oil lights all came on the dash. Then it stalled out. This is EXACTLY what happened last time my alternator died. But last time it happened, I couldnt re-start the car at all. This time, I managed to, after a few tries, re-start, pull off the road, and get to a parking lot. I pulled the CEL code, but it didnt have one in memory. So I re-started the car on the first try this time, got out on the road, and drove all the way back all 70 miles without further incident. The warning lights and stalling defeintely make me think alternator, but it was just replaced 5 months ago with a brand new one! I know someone will want to say possibly a timing issue, but the timing belt was also replaced 3 months ago, with a brand new belt, and there have been no issues at all with it. Also, the tension on the alternator/PS belt is fine, it is nice and tight. So any ideas? I have had a slight PS leak for awhile, could it possibly have lost enough fluid to do something to the alternator belt?

Earthworm · #2 03-29-2006, 03:20 PM

Check the alternator plug is not loose as well as the nut holding the wires on top.

Also check for loose battery cables. If you can turn them with 2 fingers it's too loose.

NikFu S. · #3 03-29-2006, 03:33 PM

After driving all that way if your alternator is bad or improperly connected your battery should be almost completely drained.

Get both tested at a local Autozone or by someone you trust before you go replacing anything.

oab_au · #4 03-29-2006, 03:38 PM

Quote:

Originally Posted by dwd1985

Well I havent had a serious problem in the last 2 months or so, so I am overdue. and geuss what? I was right. I had just driven down to my part-time office which is about 70 miles south from my house. No problems on the trip down at all. I was only there maybe 5 minutes tops, and then as I was leaving, I came to a stop at a stoplight, and my CEL, ABS, and Oil lights all came on the dash. Then it stalled out. This is EXACTLY what happened last time my alternator died. But last time it happened, I couldnt re-start the car at all. This time, I managed to, after a few tries, re-start, pull off the road, and get to a parking lot. I pulled the CEL code, but it didnt have one in memory. So I re-started the car on the first try this time, got out on the road, and drove all the way back all 70 miles without further incident. The warning lights and stalling defeintely make me think alternator, but it was just replaced 5 months ago with a brand new one! I know someone will want to say possibly a timing issue, but the timing belt was also replaced 3 months ago, with a brand new belt, and there have been no issues at all with it. Also, the tension on the alternator/PS belt is fine, it is nice and tight. So any ideas? I have had a slight PS leak for awhile, could it possibly have lost enough fluid to do something to the alternator belt?

Don't think it is the alternator. If there was enought power in the battery to restart the car. The alternator can stop working, and the car will still run on the batterys stored power. The oil light coming on makes me think it is an engine problem, as it is just a switch that is not affected by low voltage.

I would guess that there is some other problem that caused the stall, may be a crank sensor. These won't allways post a code, till they get worse.

Harvey.

TomsSVX · #5 03-29-2006, 04:02 PM

owning an mt SVX this is a common occurance. The car simply just stalled out. Just before the stall the lights will come on because the car is reading low voltage(not enough rpms). So basically what you want to firgure out is why the car stalled.

Tom

Trevor · #6 03-29-2006, 05:08 PM

Quote:

Originally Posted by oab_au

Don't think it is the alternator. If there was enought power in the battery to restart the car. The alternator can stop working, and the car will still run on the batterys stored power. The oil light coming on makes me think it is an engine problem, as it is just a switch that is not affected by low voltage.

I would guess that there is some other problem that caused the stall, may be a crank sensor. These won't allways post a code, till they get worse.

Harvey.

In view of the fact that CEL, ABS and the oil fault light come, the oil indication system etc. surely is not the problem, i.e. it unlikely that there are three faults.

The symptoms you describe indicate an alternator fault which has been reported here many times. However the exact cause is rather obscure and the reason, as far as I am aware, has not been previously analysed and described.

The dash indicator lights, test on turn on circuit, incorporates blocking diodes to eliminate a sneak circuit which would otherwise exist. In an event involving faults within the alternator rectifier network, alternating current is induced on line. The result is pulses of reverse voltage, dependant on engine revs., which pass the blocking diodes in the test circuit and energise the indicator lights accordingly.

NikFu S. · #7 03-29-2006, 06:34 PM

Whoa, blast from the past.

Trevor · #8 03-29-2006, 07:17 PM

Quote:

Originally Posted by NikFu S.

Whoa, blast from the past.

Greetings,

I recall thay you were party to a rather controversial debate in the distant past and unlike one other person invoved, I hold you in high regard. *>)

Cheers, Trevor.

msvx95 · #9 03-30-2006, 05:26 AM

sounds to me like your alternator maybe freezing up periodically...and your battery is low on juice....true you can run the car on just the battery if the alternator dies, but if the battery is low already.....this could be the prob.

dwd1985 · #10 03-30-2006, 01:42 PM

Well when I had my alternator replaced 5 months ago, I had the battery replaced with it. It has a 75 month warranty, so im not terribly worried about that. What is interesting to me is that I made the trip from Denver to Fort Collins (about 70 miles), and then from Fort collins to Loveland and back (about 30 miles) and then from my house to school and back (another 4 miles) without any problems. So I have run about 104 miles since the problem, without it showing up again. It is very strange. I just went out and tightened everything battery and alternator wise (even though nothing was really loose). I inspected everything I could, and didnt find any problems anywhere. Pulled the engine codes, none there. So I am at a loss for words...

spinn360 · #11 03-30-2006, 03:10 PM

an easy way to check if the altenator is bad is to disconnect the battery while the car is running. the altenator should power the car, without the batt. The altenator is supposed to power the car while driving and rejuice the batt, under normal conditions. So if the car dies then you know its the alt.(which it probably wont because if it was the alt. the car probably wouldnt still be running).

TomsSVX · #12 03-30-2006, 03:11 PM

Quote:

Originally Posted by TomsSVX

owning an mt SVX this is a common occurance. The car simply just stalled out. Just before the stall the lights will come on because the car is reading low voltage(not enough rpms). So basically what you want to firgure out is why the car stalled.

Tom

Did everyone miss this?? Your car stalled... thats it

Tom

Trevor · #13 03-30-2006, 03:19 PM

Quote:

Originally Posted by spinn360

an easy way to check if the altenator is bad is to disconnect the battery while the car is running. the altenator should power the car, without the batt. The altenator is supposed to power the car while driving and rejuice the batt, under normal conditions. So if the car dies then you know its the alt.(which it probably wont because if it was the alt. the car probably wouldnt still be running).

N.B. !!!!!!!!!!!!

Do not run the engine with the battery out of circuit. There a real danger of damaging the alternator voltage regulator due to the absence of a load.

oab_au · #14 03-30-2006, 03:20 PM

Quote:

Originally Posted by spinn360

an easy way to check if the altenator is bad is to disconnect the battery while the car is running. the altenator should power the car, without the batt. The altenator is supposed to power the car while driving and rejuice the batt, under normal conditions. So if the car dies then you know its the alt.(which it probably wont because if it was the alt. the car probably wouldnt still be running).

Danger............DANGER.

Don't do this. If the battery is disconnected while the engine is running, there is nothing to prevent the alternator from putting out high voltage, .eg 20/50 Volts. This would destroy the electronics in the car.

This used to be done in the days before electronics were common place, but in modern cars now days, it will burn them up.

Harvey.

Earthworm · #15 03-30-2006, 03:21 PM

Quote:

Originally Posted by spinn360

an easy way to check if the altenator is bad is to disconnect the battery while the car is running. the altenator should power the car, without the batt. The altenator is supposed to power the car while driving and rejuice the batt, under normal conditions. So if the car dies then you know its the alt.(which it probably wont because if it was the alt. the car probably wouldnt still be running).

Not a good idea. The alternator relies on the battery's voltage to determine how much to charge. Without it the alternator will assume the battery is dead and output extremely high voltages possibly blowing electronics of some sort.

I had a loose battery cable and was measuring voltages of 16+