OK, so somehow I must have left my lights on at the train station yesterday; must have somehow skipped out of the car so quickly that I didn't hear the alarm?:eh: Went to pick it up last night and no interior lights, no rection to ignition, etc. Luckily the missus had dropped me off and I flagged her down before she left, busted out the jumper leads and up she starts eventually, had to set the "S/W" and "3.5" but somehow the clock still seemed to keep time.

Drove home and tested a few times that it would start again. Same thing this morning, started fine.

But I've noticed that when I first get in, before I start the car, the interior lights don't turn on. If I start the car and stop it, then open the door, the lights come on fine. Thoughts?

Also there seems to be an ugly noise in the engine bay, particularly when the aircon kicks in, like a noisy injector or something, but I hadn't noticed it before the power loss?

like a noisy injector or something, but I hadn't noticed it before the power loss?
Exhaust leak? sometimes sounds like a tap tap tap tap other times like a flap flap flap?

Just wondering, when you reset the ECU, im pretty sure you have to let it idle for a while and drive it sort of "sensibly" for some time to re-teach the ECU, could that be causing the noise issues if that hasnt been done properly?

Lights, just check all the door switches and the harness' in the BEM i spose, make sure none have been damage or come loose

last time I reset the ECU, it took about 20 or so starts and about an hour of driving, then suddenly the display started working fine

Disconnect the battery when cold.

Start the engine. let it idle for 10 + minutes until it is fully hot.

If it is an auto follow the auto relearn sequence in the FAQ's.

Done.
Gerry

Exhaust leak? sometimes sounds like a tap tap tap tap other times like a flap flap flap?Could be, hard to describe and I can't quite "picture" it at the moment, what would I be looking for to diagnose this?


Just wondering, when you reset the ECU, im pretty sure you have to let it idle for a while and drive it sort of "sensibly" for some time to re-teach the ECU, could that be causing the noise issues if that hasnt been done properly?I was wondering that too, but couldn't think of any particlar link between the two.


If it is an auto follow the auto relearn sequence in the FAQ's.That's the problem with such battery faults, it always happens when you are least expecting it and have no acces to info; had to just guess/trial with the "S/W" and "3.5", at least I had previously read that somewhere and knew a tiny bit about it beforehand.
Auto seems to be operating OK, but am conscious of what I'm teaching it ; )

if you want to test for and exhaust leak cover the exhaust with you hand momentarelly and if you have plenty of pressure they is no trouble, some say holding you hand there for a long time can damage the engine in some mysterious way, but i can stall mine by covering it and it hasnt blown it yet....... lol. if there is bugger all pressure then there is a leak. it will make a whistling noise too from the leak if it isnt too bad.

first thing you need to do is charge that battery... you cant expect an alternator to charge a flat battery

first thing you need to do is charge that battery... you cant expect an alternator to charge a flat batteryYeah I'm seeing if anyone I know has a charger lying around.

first thing you need to do is charge that battery... you cant expect an alternator to charge a flat battery

As long as the battery isn't damaged, like a shorted or sulphated cell, the alternator will charge it up nicely. Half an hour of driving will kick it enough for a start the next morning. Done it plenty of times. 90 Amp output from the alternator, versus 4 Amp from a cheap charger.

As long as the battery isn't damaged, like a shorted or sulphated cell, the alternator will charge it up nicely. Half an hour of driving will kick it enough for a start the next morning. Done it plenty of times. 90 Amp output from the alternator, versus 4 Amp from a cheap charger.

now thats not what i was taught in Auto Electrician School all them years ago.... fact is an alternator keeps a full (or near full) battery full. yes you can drive around the block and then hey presto the car magically starts, but this is called a "surface charge" not a "deep charge" and soon enough you will have problems again.
in the days of old we had these things called generators that could produce power independently of the electrical system. Alternators on the other hand need power from the electrical system to produce power, and only provide what the vehicle demands (ie igniton, headlights, radio).
this is evident when you observe an alternator on a test bench, it will belt out a whopping 5A when unloaded, but keep in mind that it is taking 4A to produce those 5A and leaving you with 1A to play with. when loaded up then the alternator then starts to belt out the power until it reaches its maximum output (determined by the voltage reaching ~12.8V).

now thats not what i was taught in Auto Electrician School all them years ago.... fact is an alternator keeps a full (or near full) battery full. yes you can drive around the block and then hey presto the car magically starts, but this is called a "surface charge" not a "deep charge" and soon enough you will have problems again.
in the days of old we had these things called generators that could produce power independently of the electrical system. Alternators on the other hand need power from the electrical system to produce power, and only provide what the vehicle demands (ie igniton, headlights, radio).
this is evident when you observe an alternator on a test bench, it will belt out a whopping 5A when unloaded, but keep in mind that it is taking 4A to produce those 5A and leaving you with 1A to play with. when loaded up then the alternator then starts to belt out the power until it reaches its maximum output (determined by the voltage reaching ~12.8V).

What ??????
Alternator needs just enough voltage for the regulator to self excite for the alternator to pump out any amount of current up to maximum rating until battery voltage reaches 14.4 Volts. (Bosch regulators are clearly labeled that this is the regulated output). How much current actually goes into the battery depends on the condition of the battery. At maximum output the alternator uses about 1.5 Kw of engine power to generate the current.

I don't know about test bench numbers, but a Magna alternator will pump out about 30 amps at idle. (IIRC) Hell, people have modified alternators and used them in arc welding!

What ??????
Alternator needs just enough voltage for the regulator to self excite for the alternator to pump out any amount of current up to maximum rating until battery voltage reaches 14.4 Volts. (Bosch regulators are clearly labeled that this is the regulated output). How much current actually goes into the battery depends on the condition of the battery. At maximum output the alternator uses about 1.5 Kw of engine power to generate the current.

I don't know about test bench numbers, but a Magna alternator will pump out about 30 amps at idle. (IIRC) Hell, people have modified alternators and used them in arc welding!

im sorry you feel this way but it is what it is.
regulated output is just the voltage control without it the alternator can throw out 30V but volts dont charge a battery... too many will fry a battery and most all the other electrics.
the alternator will pump out 30A because thats what is being asked of it by the electrics, but it still needs a good battery to do this.
yes alternators can be used to arc weld but thats another kettle of fish.

alternators are the answer to higher revving engines on vehicles that consume a lot of power, but they cant give a proper charge to a flat battery... EOS

I don't want to hijack thread but i figure it's better than starting a new one,

I have a TJ Magna Sports and I am having the exact same issue !, My car used to fire straight away, now it takes a good 3-4 seconds turning over, every single time I get in the car and start it, the ECU resets, i have to press through the '5' and "3.5" menus.

I have the thing with the interior lights also, only sometimes do they come on and its only for a few seconds, then flicker out.

Solution ?

Voltage on start is dropping too low, is my guess.

Try cleaning the battery connections, if no better try a fresher battery. And check the alternator output, should be 14.4 volts at the battery with the engine running.

Alternator comments.

Alternators have much higher outputs than the old school generators.
Industry changed to alternators because use of parking lights which were mandatory overnight a long time ago in the UK, plus the amount of electrical equipment was starting to be increased as well as the fact that the generators of the time were not capable of outputting enough power in urban driving to recharge the battery in a reasonable time.

One post referred to 30A output at around idle. About right, the reason for this is to be able to recharge the battery quickly in low speed urban driving.
Daughter, several times, left the interior light on in her car. All i would do is to charge the battery enough with the charger, or jump start it. Then go for a 30 minute local highway drive. This was always enough to get enough charge back in the battery.

Alternators have electronic voltage control, the old school generators had a relay system that was just a bit binary.

Never read so much uninformed rubbish about alternators in my life.

Gerry

i have had about 10 flat batteries in my magna, and not once did i need to put it on charge. just got a mate to give it a push, and away she went. it only went flat when i used the stereo for ages with the motor off, or if i left the lights on overnight. it had a 75 amp hour bosch deep cycle in it. something like 1000cca

Alternator comments.

Alternators have much higher outputs than the old school generators.
Industry changed to alternators because use of parking lights which were mandatory overnight a long time ago in the UK, plus the amount of electrical equipment was starting to be increased as well as the fact that the generators of the time were not capable of outputting enough power in urban driving to recharge the battery in a reasonable time.

One post referred to 30A output at around idle. About right, the reason for this is to be able to recharge the battery quickly in low speed urban driving.
Daughter, several times, left the interior light on in her car. All i would do is to charge the battery enough with the charger, or jump start it. Then go for a 30 minute local highway drive. This was always enough to get enough charge back in the battery.

Alternators have electronic voltage control, the old school generators had a relay system that was just a bit binary.

Never read so much uninformed rubbish about alternators in my life.

Gerry

lol for those not willing to accept the facts i give you this taken from the RACQ website:
http://www.racq.com.au/motoring/roadside_assistance/racq_batteries/battery_myths



We answer some common battery myths.

I left my lights on for a few hours and discharged (flattened) the battery. A drive for half an hour should charge it up.

FALSE. There are several factors which will always prevent a vehicles charging system from fully recharging a battery. Issues such as how much power from the alternator is diverted to the battery, how long the alternator power is available, the size and depth of discharge of a battery and the temperature all work against restoring a battery to an acceptable level of charge. It must be recognised that normal or extended driving, Idling the engine for periods of time, short stop-start trips, driving in hot or cold weather or at night will not fully recharge a battery. Surface charging or continuous undercharging will lower the capacity of the battery over time and deep discharges can damage batteries and will shorten their lives. When a discharged (flat) battery needs to be recharged, the only way to reliably restore it is to use an appropriate multi-stage battery charger. The charger voltage needs to be high enough to mix the battery acid evenly in the electrolyte to prevent ‘stratification’. You will also save wear and tear, and fuel by using a charger to restore the battery to its maximum charge..

I don't drive my car that often and sometimes go away for several weeks and now the battery is discharged (flat). Is it normal for a battery to go flat if the car is not driven?

TRUE. Batteries have a natural self discharge or internal chemical leakage. All modern vehicle electrical systems draw a tiny amount of power from the battery when not in use. This is normal to keep all the electrical systems ‘alive’. Over time the battery will become fully discharged if not driven. The only way to overcome this is to use the vehicle regularly or connect a maintenance charger, which will keep your battery in good condition.

The battery was discharged (flattened) a few months ago and I've had the car jump started a couple of times. The battery is less than twelve months old, shouldn't it be replaced under warranty?

FALSE. No amount of driving will recharge a discharged battery to a reliable level. A discharged battery is generally a good battery. By correctly recharging it using an appropriate charger will in most cases restore the battery condition and prevent further breakdowns. You should also have your charging system inspected to ensure it’s producing enough power. It’s also possible the culprit draining the battery is a boot light or accessory left on. RACQ Patrols can test your battery and electrical system. If needed RACQ sell a range of chargers at member prices. Go to RACQ Batteries for all the details.

i have had about 10 flat batteries in my magna, and not once did i need to put it on charge. just got a mate to give it a push, and away she went. it only went flat when i used the stereo for ages with the motor off, or if i left the lights on overnight. it had a 75 amp hour bosch deep cycle in it. something like 1000cca

yeah thats the good thing about deep cycle batteries... and besides even if it was at 80% DOD you would still have 200CCA's to get the car started

lol As if the RACQ is an expert on anything!

I gave up my RAA (equivalent of RACQ in SA) membership years ago because of some of the dumbed down and downright incorrect information they were pushing. They were like pushing the message "You are pretty dumb, we are the experts, don't question us, you need us."

Twaddle!

lol As if the RACQ is an expert on anything!

I gave up my RAA (equivalent of RACQ in SA) membership years ago because of some of the dumbed down and downright incorrect information they were pushing. They were like pushing the message "You are pretty dumb, we are the experts, don't question us, you need us."

Twaddle!

i'll agree with that (i've had my dealings with customers who blindly believe the RAC's half assed and totally incorrect diagnosis.... usually ends in an argument)
but the facts about the charging system stand, and quite frankly im too busy and dont have the mental fortitude at the moment to bother arguing the point.

i'll agree with that (i've had my dealings with customers who blindly believe the RAC's half assed and totally incorrect diagnosis.... usually ends in an argument)


Nice to see we agree on something!

Something I noticed last night that I hadn't noticed before "the incident", but may be normal; the light in the central power windows switch is on permanently, even when the car is locked? Is that normal, or another thing gone dodgy?
(this is a TL BTW)