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zapp-whyzz

Charging Problems Yaris 2002

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Hey, New to all this, but really need help.

I've got a 2002 1.0 Yaris, and about 2 months ago, i had a flat Battery... so i checked the Battery and the alternator and it seemed to be charging o.k at about 14.2 volts, so after a new Battery was fitted, it all seemed fine.

then about 2 weeks ago, driving along, car just ground to a halt, no power, Battery was totally flat again. A jump start later, and i got on my way. This time, the alternator wasn't charging the Battery at all, and it died again soon after.

So i changed the Alternator, and it's ran fine for 10 days........ then you guessed it...... driving home, lights on, radio on.... it dies again.... Battery was dead.......

Jump started it, and it ran again..... Battery charging at 14v with nothing on, and 13.6v with lights and heater on...and with the engine off, sitting about 12.4v.

I'm at a loss...

The earth tested fine from the "-" to the car body, but from the Battery to the engine block, it was like a pulse from the continuity tester...?

any suggestions folks would be greatly appreciated...

also, i'm noticing a ticking noise from a sensor located on the right hand side of the air box, it has a multi-plug on it, and 2 pipes? anyone know what that is?

Thanks

Zapp

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It could be a voltage regulator fault.

where would i find that? i checked the Main fuses in the under bonnet fuse/relay box, they seem o.k.

I thought the regulator was in the alternator, but wansn't sure if the ECU took on that task?

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I believe the rectifier and voltage regulator are contained within the alternator housing. Sounds like you deffo have a charging probem, To check the alternator output effectively you really need a voltmeter and an ammeter.

From memory the no load voltage ought to be around 14.7 volts at around 2000 rpm.

With headlights on high beam and heater blower on full, heater rear window on, wipers on, ammeter ought to read around 30 amps at around 2000 rpm.

That's from memory and sometimes my memory is a bit undercharged :unsure:

Don't leave your Battery at 12.4 volts, standing voltage should be around 12.8 volts, below 12.5 volts it'll get knackered, charge it up.

Just did a quick search and found this

Hope this helps

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A poor continuity test from the Battery negative terminal could denote either a faulty engine earth lead or the alternator ain't earthing correctly. Check the engine eath lead is in good nick.

Are you getting any warning lights on the dash? Your Battery voltage reading of 12.4 volts is within normal parameters.

Also remember a voltage reading across it's terminals is a poor guide to its condition. Look at it this way!! If you connected eight "AAA" batteries end to end you would get a reading of 12+ volts but obviously they would be capable of illuminating the lights never mind starting an engine.:)

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A poor continuity test from the battery negative terminal could denote either a faulty engine earth lead or the alternator ain't earthing correctly. Check the engine eath lead is in good nick.

Are you getting any warning lights on the dash? Your battery voltage reading of 12.4 volts is within normal parameters.

Also remember a voltage reading across it's terminals is a poor guide to its condition. Look at it this way!! If you connected eight "AAA" batteries end to end you would get a reading of 12+ volts but obviously they would be capable of illuminating the lights never mind starting an engine.:)

Hey,

replaced the earth strap yesterday, cleaned up the area it was attaching too, and all seemed to be good, charging at 14v constantly and earth contuinuity was good, then after about 10 minutes driving home, the voltmeter(i have left it connected to keep an eye on it during normal driving, Dropped to 12.2v and stayed there, the Battery lamp DID NOT illuminate. i made it home and checked out all the wiring, and all seemed to be well connected, all connectors were tight, and the miltiplugs were all "fully home"... by this time it was getting dark, so i left it till this morning, where the Battery tested at 12.6v, and after starting, back up at 14.0v...?

i'm truly puzzled now!

i've asked 2 mechanics that are local to me, and both of them are at a loss...

nothing changed between last night and this morning, yet this morning it was fine again.

Also, i had driven the car for 30 minutes going to the garage to fit the new earth strap, and it was fine, yet 10 minutes into the home bound journey, it dropped to 12.2volts? then this morning it was fine again...?

there must be an answer, but not sure what other tests i can do to get to the bottom of it.

Also, i connected the vehicle to a Bosch KTS200, and there were no error codes, nothing stored at all.

and out of interest, i disconnected the alternator and started the vehicle, and the Battery warning lamp came on, so it does seem to come on when the Battery is not getting a charge, but didn't when the voltage dropped on the journey home....

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Hi,

When the voltage drop occurs do all the electrics (lights, heater,sound system etc) work as they should?(could be that something is shorting)Do the lights go a lot dimmer etc? Also the next time this happens check to see if the Battery terminals are getting hot. Also are the Battery terminals the correct size and fitment for the connecting poles on the Battery itself?

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Hi,

When the voltage drop occurs do all the electrics (lights, heater,sound system etc) work as they should?(could be that something is shorting)Do the lights go a lot dimmer etc? Also the next time this happens check to see if the battery terminals are getting hot. Also are the battery terminals the correct size and fitment for the connecting poles on the battery itself?

the only thing i noticed at the time was the Heater Got slower(you heard the drop in noise more than felt it), i will check the terminals next time for sure. The Battery was a Toyota supplied one, OE part from the dealership along the road.

the terminals are nice and clean, and originals, the are fitted nice and securely to the Battery, and show no signs of any blackening from a short, neither does the terminal on the alternator.

thanks for your help so far.

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The voltage dropping from 14v to 12v means that you lost charge from the alternator at that time.

You'll see 14v when the alternator is running and charging the Battery properly and 12v when its not and the Battery is supplying all the power on its own.

Its definately an issue with the alternator charging system somewhere - maybe the regulator (in the alternator) is cutting out somehow...

What's strange is that you've changed the alternator - that's the bit that I don't udnerstand as if you hadn't done that already, I'd have definately said that was your issue....

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The voltage dropping from 14v to 12v means that you lost charge from the alternator at that time.

You'll see 14v when the alternator is running and charging the battery properly and 12v when its not and the battery is supplying all the power on its own.

Its definately an issue with the alternator charging system somewhere - maybe the regulator (in the alternator) is cutting out somehow...

What's strange is that you've changed the alternator - that's the bit that I don't udnerstand as if you hadn't done that already, I'd have definately said that was your issue....

that's what's getting me too, the fact it's a new alternator.

Old Battery + Old Alternator = Flat Battery while driving

New Battery + New Alternator + new belt = Flat Battery while driving

+New Earth Strap = Loss in charging from14v to 12v...

(no squeal from belt either, and is tensioned perfectly.)

left overnight, tested again, and fine 14v again.

there's no damage to the miltuplug on the alternator, and i followed the wiring back, and there is no damage to the wiring in the harness either.

It's a strange one!

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You say you had a drop in vo;ltage but is it enough to make the Battery flat again? If it is charging and starting over a few months, then you may be over-reacting to a remedied fault!

You may well have had a drop in voltage as the engine fan cut in as the car got warm. If you use more power then you are charging back in, there will be a drop.

Usually, the charging system will only work above a certain rpm, (say 2-3000) so if you use power, lights, stereo, rear window heater, on slow, stop start short trips, the Battery won't get charged much. Longer, faster journeys it will chage better.

BTW, I mentioned the rear window heater.... These can absolutely kill a Battery dead, if you forget to turn them off as the drain is very high. (So too, are foglights)

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You say you had a drop in vo;ltage but is it enough to make the battery flat again? If it is charging and starting over a few months, then you may be over-reacting to a remedied fault!

You may well have had a drop in voltage as the engine fan cut in as the car got warm. If you use more power then you are charging back in, there will be a drop.

Usually, the charging system will only work above a certain rpm, (say 2-3000) so if you use power, lights, stereo, rear window heater, on slow, stop start short trips, the battery won't get charged much. Longer, faster journeys it will chage better.

BTW, I mentioned the rear window heater.... These can absolutely kill a battery dead, if you forget to turn them off as the drain is very high. (So too, are foglights)

Hi, yes the drop in voltage was enough for the Battery to go flat again, the vehicle was driven for approx 40 minutes, and after that time, the vehicle just stopped, and wouldn't start again. a jump start from another vehicle got it going again, and the charging was restored.

The journey was originally a 35 mile trip on 60>70 mph roads, so the revs were higher than needed. but is still stopped charging, and stopped with a flat Battery.

The strange thing is that the Battery light doesn't come on, even when the alternator is not charging the Battery. The Warning lamp does work, because i tested it by disconnecting the alternator main + lead, and started the engine, and it came on. but when the voltage drops to 12v and below when driving, it does not come on at all.

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sounds like you have a faulty wireing connector somewhere, then! Time to get it to an auto-electrician, if possible as it could be anywhere. Do not rule out anything you may have already replaced, though... ometimes they are duff from new or may be wrongly installed. Start from scratch, testing the likeliest things first, working methodically. Some cars had what are refered to as fuseble links.... they are like non diy fuses, that take a large lump of power but can blow. You then need it removed and another soldered in its place. I would seek professional help after re-checking the stuff I replaced.

I also remember, once on an old Lada, I had whet was called a dry joint!

I had changed an alternator 3 times before taking it to the auto electrician... He found the dry joint and repaired it, no probs after that. It was basically a soldered joint that had fractured so sometimes current passed through and it worked, sometimes it was too open and wouldn't work, making it go flat again. I had the same thing happen on a nearly new (Then) T.V. which, when the joint got hot, the t.v. cut out, on cooling, it came back on.. It was like someone had pressed the standby button. I could see the joint spark here and, as it was a heavy t.v. I soldered it myself as the seller said I needed to return it for the repair. (No change there, then)

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sounds like you have a faulty wireing connector somewhere, then! Time to get it to an auto-electrician, if possible as it could be anywhere. Do not rule out anything you may have already replaced, though... ometimes they are duff from new or may be wrongly installed. Start from scratch, testing the likeliest things first, working methodically. Some cars had what are refered to as fuseble links.... they are like non diy fuses, that take a large lump of power but can blow. You then need it removed and another soldered in its place. I would seek professional help after re-checking the stuff I replaced.

I also remember, once on an old Lada, I had whet was called a dry joint!

I had changed an alternator 3 times before taking it to the auto electrician... He found the dry joint and repaired it, no probs after that. It was basically a soldered joint that had fractured so sometimes current passed through and it worked, sometimes it was too open and wouldn't work, making it go flat again. I had the same thing happen on a nearly new (Then) T.V. which, when the joint got hot, the t.v. cut out, on cooling, it came back on.. It was like someone had pressed the standby button. I could see the joint spark here and, as it was a heavy t.v. I soldered it myself as the seller said I needed to return it for the repair. (No change there, then)

yesterday i checked.

Alternator multi-plug.

Alternator Multi-plug wiring back to main harness.

Belt tension.

Main "+" Cable from Alternator.

Battery condition and charge.

"-" terminal at Battery.

"+" terminal at Battery.

"-" earth strap to body.

"-" earth strap to gearbox.

"-" earth strap to Alternator.

120A Alternator Fuse.

80A Starter Fuse.

all connections and multi-plugs to ECU behind glovebox.

all under bonnet fuses.

all internal fuse box fuses.

Continuity of connections from terminals to alternator.

All in good working order...

Booked it in to Auto electrician for next Tuesday. £55.00+vat per hour..... hope it's a simple fast fix!!

i'll post what they find.

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sounds like you have a faulty wireing connector somewhere, then! Time to get it to an auto-electrician, if possible as it could be anywhere. Do not rule out anything you may have already replaced, though... ometimes they are duff from new or may be wrongly installed. Start from scratch, testing the likeliest things first, working methodically. Some cars had what are refered to as fuseble links.... they are like non diy fuses, that take a large lump of power but can blow. You then need it removed and another soldered in its place. I would seek professional help after re-checking the stuff I replaced.

I also remember, once on an old Lada, I had whet was called a dry joint!

I had changed an alternator 3 times before taking it to the auto electrician... He found the dry joint and repaired it, no probs after that. It was basically a soldered joint that had fractured so sometimes current passed through and it worked, sometimes it was too open and wouldn't work, making it go flat again. I had the same thing happen on a nearly new (Then) T.V. which, when the joint got hot, the t.v. cut out, on cooling, it came back on.. It was like someone had pressed the standby button. I could see the joint spark here and, as it was a heavy t.v. I soldered it myself as the seller said I needed to return it for the repair. (No change there, then)

yesterday i checked.

Alternator multi-plug.

Alternator Multi-plug wiring back to main harness.

Belt tension.

Main "+" Cable from Alternator.

Battery condition and charge.

"-" terminal at Battery.

"+" terminal at Battery.

"-" earth strap to body.

"-" earth strap to gearbox.

"-" earth strap to Alternator.

120A Alternator Fuse.

80A Starter Fuse.

all connections and multi-plugs to ECU behind glovebox.

all under bonnet fuses.

all internal fuse box fuses.

Continuity of connections from terminals to alternator.

All in good working order...

Booked it in to Auto electrician for next Tuesday. £55.00+vat per hour..... hope it's a simple fast fix!!

i'll post what they find.

Hi- did you get this fixed? What was the problem? I have a similar fault on my new Yaris (The dealer has had it 14 days trying to find the fault)

I noticed the heater blower speed kept fluctuating. As you drive along the blower speed suddenly drops - if I lift my foot off the accelerator after 1-2 seconds it speeds up again, foot back on pedal and it slows down again. (If the sidelights or headlights are turned on it does not do it at all- it runs at normal speed constantly)

They have changed the alternator and it is still doing it. The tech told me the ecu sends a a signal to the alternator to boost output when the blower, lights or heated window are turned on- a signal for each one. If I turn the lights on the blower speed does not fluctuate because the alternator's output is boosted.

They think it might be a problem with the ecu. When they tested it the voltage was dropping below 12v at times.

Toyota dealer is struggling with this. They even had a tech out from Toyota GB - he diagnosed the alternator! just waiting to see what they are gonna do.

Would love to hear what the problem turned out to be on your car as it sounds like it could be a similar problem.

An American Yaris owner told me a car over there had this problem and the dealer had to change the entire wiring loom as there was a bad earth/ground issue

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On ‎2‎/‎18‎/‎2010 at 5:29 PM, zapp-whyzz said:

yesterday i checked.

Alternator multi-plug.

Alternator Multi-plug wiring back to main harness.

Belt tension.

Main "+" Cable from Alternator.

Battery condition and charge.

"-" terminal at Battery.

"+" terminal at Battery.

"-" earth strap to body.

"-" earth strap to gearbox.

"-" earth strap to Alternator.

120A Alternator Fuse.

80A Starter Fuse.

all connections and multi-plugs to ECU behind glovebox.

all under bonnet fuses.

all internal fuse box fuses.

Continuity of connections from terminals to alternator.

All in good working order...

Booked it in to Auto electrician for next Tuesday. £55.00+vat per hour..... hope it's a simple fast fix!!

i'll post what they find.

I know its been about 9 years, but could someone tell me what was the conclusion of this issue.

Im experiencing the same issue on my 2006 Yaris 1.4 diesel.

Alternator is good

Battery is good

however voltage is 12.4 and over time the Battery goes

Please help a brother out otherwise it will be an expensive trip to the electricians!

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7 minutes ago, Yaardost said:

I know its been about 9 years, but could someone tell me what was the conclusion of this issue

The OP hasn't visited the club since February 2010, so we're unlikely to find out the outcome now.

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can anyone give any advice whether the wiring or the ecu might be the culprit based on your experience?

from what it sounds like it could be a dry joint somewhere, any guidance much appreciated! :biggrin:

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Get yourself a multimeter.

Start the car, don't turn lights or anything, check Battery voltage, should be around 14.5, bit more or less it's fine, it means the alternator is charging.

If that's all ok, i would do a parasitic drain test, basically you use multimeter as a middleman to see how much current your car is drawing from the Battery when off.

If car is drawing over 30-50 milliamps or so, then you have a parasitic drain. So you take fuses one by one, checking the numbers until you find the culprit.

It could also be possible your alternator is the one draining the Battery when the car is off.

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You don't say whether the 12.4V you measure is with the engine stopped or running. Stopped at rest and that value is fine. When running the voltage may switch between around 14.5V and 12.5V as the ECU actively controls the alternator as an aid to emissions and economy.

The original post of:

Quote

I noticed the heater blower speed kept fluctuating. As you drive along the blower speed suddenly drops - if I lift my foot off the accelerator after 1-2 seconds it speeds up again, foot back on pedal and it slows down again. (If the sidelights or headlights are turned on it does not do it at all- it runs at normal speed constantly)

actually sounds normal if that vehicle also had such a system. The alternator output increases when decelerating because it is effectively 'free' energy available to turn it. 

 

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