Battery Light ON, then lost power steering, then car died.

[Lex_utor]

Hi. So yesterday I noticed my Battery light was ON. I don't drive much. But drove on Friday and everything seemed ok. Didn't drive during the weekend and yesterday, Battery light was ON. I drove a little bit, to charge it, as I had the problem before of the Battery dying on me after not driving for a few weeks. For a moment, the light went away. But came back again. Today, it was ON again. I drove off and on my way back, I lost power steering and the whole dash lit up like a Christmas tree. ABS light, VSC Light, airbag light, and of course the Battery light. Then very close to home the dash started flashing ON and OFF and the needles going up and down as they do when you turn the car on. As I turned in my street everything went dark and the engine started loosing power. I barely made it to my house and had to park up front. The engine didn't have power to drive in. All was dark and engine had no power. Glad I at least made home.

Now, obviously something related to power. Can a bad Battery do that? Or is all this a clear sign of a bad alternator? I have a Battery charger. Is it worth it connecting? To at least being able to drive the car in the garage? Or if this has damaged the Battery it can de dangerous? I seem to remember something in the charger manual not to connect to a damaged Battery. But the manual is gone.

Thanks as always for the help gentlemen. 

 

Cheers.

[Mr Vlad]

Hi Lex. I'm sorry to tell you that I had Exactly that and it was indeed the Alternator. Considering the age of your car too its the Alternator gone.

I managed to get mine to Lexus to sort as I was desperate because I was going away that day. It cost £800 but I did get a free loan car for actually 4 days.

[Lex_utor]

Hi Vlad. How have you been? 🙂

Thanks for the quick reply.

Is it worth it trying to charge the Battery? I can't even get the cart to a mechanic, without towing.

But I'm thinking of doing it myself at home. Is it a dread, like changing spark plugs in the IS? Anything I should watch for, if I don't buy a Lexus part?

[Malc1]

are you with the RAC / AA ?

Malc

[Lex_utor]

I'm not in the UK. 🙂 

[Malc1]

do you have the local breakdown cover ?  to ask them to tow you wherever, ?

Malc

[Lex_utor]

I'm with our local car club. I have used them to tow me for free once when I broke down on the motorway (not the Lexus). They only tow it directly to a garage/mechanic. But now the car is at home, so I'm not sure if they would still do it. Plus, I'm not entirely sure I want to leave 800-1000 Euros at the mechanic to sort his out. I might do it myself, if it's not too complicated?

[ahmedali44]

Use  voltmeter and see what voltage it's showing and take Battery off charge overnight and see if charge's  my last Battery was Toyota original one tried charging overnight but was totally dead 

[H3XME]

Like Vlad said, it's most likely the alternator. Try charging the Battery over night. Check with the volt meter. 

Have a look at this video and see if you think it's difficult or not. "easy" is down to personal opinion/skillset. 

 

[Spock66]

A Voltmeter will also give an indication of whether the alternator is charging, should be around 14V with the engine running, also check it under heavy load (headlights, rear screen heater, blower fan, heated seats etc).

[Mr Vlad]

Hi Lex. An good thanks. Not seen you on here for a while. I'm missing my beloved is250 after writing it off.

As stated above yes charge the batter ideally with a smart charger. The reconnect the Battery and your car should start but with probably some lights on your dash. Your car should have enough Battery power to get you to a garage you trust to fit a genuine Toyota/Lexus alternator. 

I charged the one on mine and it got me 18 miles to the Lexus dealer. 

A competent mechanic should be able to change the alterations. If you feel confident then first have a look where it is and how accessible it is. From what I remember it's not an easy job.

[Lex_utor]

39 minutes ago, H3XME said:

Like Vlad said, it's most likely the alternator. Try charging the battery over night. Check with the volt meter. 

Have a look at this video and see if you think it's difficult or not. "easy" is down to personal opinion/skillset. 

 

Well, it only takes about 12 mins. right? Can't be that hard. 😄

In all seriousness, I don't have a fully equipped shop or the expertise. I'm no mechanic and never did this before. But even if it takes me the whole Saturday, as long as I can finish it, I guess it's worth it to save 800-1000 quid. I have most of the tools. I'm not sure if he used a special tool to take those studs off, so he didn't have to take off the AC box. Or if that is just a small socket? Need to get a mirror. And the tool for the belt removal, just a normal ratchet with the correct size socket will do or is there something else?

Hardest part seems to be that one bracket. I'm also guessing it's easier to do the job coming from the top than from the bottom of the car?

At least I don't have to remove all the top plastic clad. Mine are all off already. 🙂

 

 

[Lex_utor]

4 minutes ago, Mr Vlad said:

Hi Lex. An good thanks. Not seen you on here for a while. I'm missing my beloved is250 after writing it off.

As stated above yes charge the batter ideally with a smart charger. The reconnect the battery and your car should start but with probably some lights on your dash. Your car should have enough battery power to get you to a garage you trust to fit a genuine Toyota/Lexus alternator. 

I charged the one on mine and it got me 18 miles to the Lexus dealer. 

A competent mechanic should be able to change the alterations. If you feel confident then first have a look where it is and how accessible it is. From what I remember it's not an easy job.

Sorry to hear about the write off. 😞

 

Yeah, I need to have a look and see if I think I can do it.

[Lex_utor]

So...after sitting for 3 hours, the car started. So I could at least manage to drive it into my garage at home. But this is strange, as when I came home the car just died and wouldn't restart. Internal dome light was still on etc. But engine wouldn't start and dash wouldn't light up.  Now it started almost on que. And power steering was ON. Then the power steering quickly went. Very hard to turn in the the garage. But the car didn't die again. I would have thought if it was dead before it would remain dead? Because it presumably died because the Battery was dead. So how did it get enough juice to start now? 

[Linas.P]

2 hours ago, Lex_utor said:

Is it worth it trying to charge the battery?

You can check the Battery, you can also charge the Battery and it will get you ... I don't know - 10-15 miles just on the Battery. 

2 hours ago, Lex_utor said:

Is it a dread, like changing spark plugs in the IS? Anything I should watch for, if I don't buy a Lexus part?

Changing spark plugs is easy, I can do it in 15 minutes. There is literally a single bolt behind the throttle body which is tricky, the rest is very straight forward. 

Changing alternator is ABSOLUTE PAIN, basically all the bolts are blind and there is no space. if you get socket inside then socket backs-up into the chassis rail. I tend to believe it is easier from underneath of the car, but still in terms of pain factor it is easy 8/10, spark plugs on IS250 would be 3/10 in my opinion.

Have I done worse - yeah sure - replacing Engine Harness No1 on the car without removing engine and gearbox is way worse (it also requires removing alternator just to get to crank position sensor). That would be easy 11/10, but alternator on IS250 is up there in less then nice jobs.

Alternator could also be easily tested.

So I would start from charging the Battery and then testing voltages. Charged Battery should be anywhere between 12.4-12.8v. Above 12.8v is "surface charge" which will disappear after few minutes with headlights on. Anything below 12v is either Battery not charged or faulty. Then if you can start the car (you should be able to after charging it), then voltage should read something ~13.8v-14.4v. 14.4v is absolutelly perfect new alternator without anything running on the car, so on heathy alternator you will see something ~ 14v. IS250 with engine running should be something like 14.2v on new alternator, I have checked mine few times and it jumps around a little bit 13.96v maybe to 14.21v, but give or take averages above 14v. That is good. Anything below 13.8v is considered bad, but you can easily run the car just fine, but it just takes longer to charge the Battery and eventually when you have few things on, heated seats, music playing, high beam, phone charging etc... you could get to the point where alternator does not generate enough power to even run the car. I forgotten what is the trigger point for fault (assume something like below 13.4v), but basically what Battery light means is that your input voltage from alternator dropped below that level. Hence when you turn ignition on it shows Battery light (because Battery is 12.8v at most), but when you start the engine Battery light goes away.

[Linas.P]

1 hour ago, Lex_utor said:

I have most of the tools. I'm not sure if he used a special tool to take those studs off, so he didn't have to take off the AC box. Or if that is just a small socket? Need to get a mirror. And the tool for the belt removal, just a normal ratchet with the correct size socket will do or is there something else?

Hardest part seems to be that one bracket. I'm also guessing it's easier to do the job coming from the top than from the bottom of the car?

Yes all normal tools and sockets will do, ideally you should have mirror or even better camera (borescope). Loads of lights as well. Yes you can remove belt-release tensioner with normal socket or spanner.

The trick for me was having multiple thickens of sockets, so deep sockets, short sockets and then set of extensions. Basically the trick is to match socket and extension length so that you can reach the bolts for the brackets, but they are not too long so that they back-up into rail. and then basically you undo the bolt, maybe half way, then change to shorter socket, then in the end use fingers or small spanner. Flex joints are also good idea.

As I said - should be easier to do from underneath the car, but just marginally, space there just sucks. First time it took me good 2 hours an a lot of cursing just to remove alternator. So for replacement I would say 4 hours. Obviously could be done quicker when you get used to it.

[Lex_utor]

On 2/20/2024 at 6:38 PM, Linas.P said:

You can check the battery, you can also charge the battery and it will get you ... I don't know - 10-15 miles just on the battery. 

Changing spark plugs is easy, I can do it in 15 minutes. There is literally a single bolt behind the throttle body which is tricky, the rest is very straight forward. 

Changing alternator is ABSOLUTE PAIN, basically all the bolts are blind and there is no space. if you get socket inside then socket backs-up into the chassis rail. I tend to believe it is easier from underneath of the car, but still in terms of pain factor it is easy 8/10, spark plugs on IS250 would be 3/10 in my opinion.

Have I done worse - yeah sure - replacing Engine Harness No1 on the car without removing engine and gearbox is way worse (it also requires removing alternator just to get to crank position sensor). That would be easy 11/10, but alternator on IS250 is up there in less then nice jobs.

Alternator could also be easily tested.

So I would start from charging the battery and then testing voltages. Charged battery should be anywhere between 12.4-12.8v. Above 12.8v is "surface charge" which will disappear after few minutes with headlights on. Anything below 12v is either battery not charged or faulty. Then if you can start the car (you should be able to after charging it), then voltage should read something ~13.8v-14.4v. 14.4v is absolutelly perfect new alternator without anything running on the car, so on heathy alternator you will see something ~ 14v. IS250 with engine running should be something like 14.2v on new alternator, I have checked mine few times and it jumps around a little bit 13.96v maybe to 14.21v, but give or take averages above 14v. That is good. Anything below 13.8v is considered bad, but you can easily run the car just fine, but it just takes longer to charge the battery and eventually when you have few things on, heated seats, music playing, high beam, phone charging etc... you could get to the point where alternator does not generate enough power to even run the car. I forgotten what is the trigger point for fault (assume something like below 13.4v), but basically what battery light means is that your input voltage from alternator dropped below that level. Hence when you turn ignition on it shows battery light (because battery is 12.8v at most), but when you start the engine battery light goes away.

Thanks. I was out of town for 2 weeks for work. I charged the Battery overnight before I left. I just came back Friday, so now I'm looking into this again. I charged the Battery fully, car will start but Battery light is still ON. I didn't measure it yet. I get how to measure the Battery. but as far as measuring the voltage for the alternator, you do that through the Battery? For the Battery you measure the Battery poles with the engine off and for the alternator you measure the Battery poles with the engine running? 

[Lex_utor]

On 2/20/2024 at 7:01 PM, Linas.P said:

Yes all normal tools and sockets will do, ideally you should have mirror or even better camera (borescope). Loads of lights as well. Yes you can remove belt-release tensioner with normal socket or spanner.

The trick for me was having multiple thickens of sockets, so deep sockets, short sockets and then set of extensions. Basically the trick is to match socket and extension length so that you can reach the bolts for the brackets, but they are not too long so that they back-up into rail. and then basically you undo the bolt, maybe half way, then change to shorter socket, then in the end use fingers or small spanner. Flex joints are also good idea.

As I said - should be easier to do from underneath the car, but just marginally, space there just sucks. First time it took me good 2 hours an a lot of cursing just to remove alternator. So for replacement I would say 4 hours. Obviously could be done quicker when you get used to it.

Oh man. Not very encouraging.  As far as doing it from underneath, I have no lift. I only have those ramps, so the car front is lifted a few centimeters off the ground. You have to lay underneath the car. This is what I meant when I said from under. Probably better from the top then, under these circumstances?

[Linas.P]

20 minutes ago, Lex_utor said:

For the battery you measure the battery poles with the engine off and for the alternator you measure the battery poles with the engine running? 

Correct. For Battery you need 12V+ at minimum. 11.63V is considered 0% charged, 12.89V is 100% charged -12.4-12.6V is what you should normally expect for good Battery. For alternator - ideally 14V+ (14.4V theoretical maximum, but in practice ~14.2 is achievable), but 13.8-13.9V still good enough.

16 minutes ago, Lex_utor said:

Probably better from the top then, under these circumstances?

Will suck either way... from below you will have benefit of seeing what you can't reach, from the top you have benefit of reaching what you can't see. 

[Lex_utor]

On 3/12/2024 at 2:56 PM, Linas.P said:

Correct. For battery you need 12V+ at minimum. 11.63V is considered 0% charged, 12.89V is 100% charged -12.4-12.6V is what you should normally expect for good battery. For alternator - ideally 14V+ (14.4V theoretical maximum, but in practice ~14.2 is achievable), but 13.8-13.9V still good enough.

Will suck either way... from below you will have benefit of seeing what you can't reach, from the top you have benefit of reaching what you can't see. 

I measured it. Battery was under 12V and with the engine running, under 11. But I'm not sure how accurate this is. It's an old multimeter and it's first time I done this. The Battery was not freshly charged though. I fully charged it a week or so ago and since then I have started the car to move it a few times. But regardless, if it reads lower with the engine running it can only mean the alternator is not doing its thing right. If the measurements are accurate. 

[Linas.P]

7 hours ago, Lex_utor said:

I measured it. Battery was under 12V and with the engine running, under 11. But I'm not sure how accurate this is. It's an old multimeter and it's first time I done this. The battery was not freshly charged though. I fully charged it a week or so ago and since then I have started the car to move it a few times. But regardless, if it reads lower with the engine running it can only mean the alternator is not doing its thing right. If the measurements are accurate. 

Alternator is dead. Battery probably is simply low, because alternator isn't charging it at all. Did you say it was changed few years ago?

Even if you have dead Battery (say 11V) when engine is running you should still get close to 14V, it may be slightly lower since the Battery is so dead, but it should never be under 11V. In fact if you Battery was under 12 by itself and it drops to under 11 when engine is running, I reckon alternator is not running at all and engine is simply running on Battery.

Math here is relatively simple - so let's say maximum charge in the Battery is 12.8-12.9V, running the engine requires minimum of 0.3V, so if your alternator is outputting say 13.2V, it would barely charge the Battery.

First of all, I suggest you charge the Battery again, confirm it is NO LESS than 12.4-12.6V. Start the engine again and if you get less than what you measured before starting the engine  - it is 100% alternator. I am already sure it is alternator, but technically you should not even start measuring it unless Battery itself is 12+.

Second thing, you can measure the voltage between alternator plug and body ground. You will see thick positive cable going to alternator and on the alternator there is rubber boot with hole at the top, basically you can stick your positive probe into that hole and that is your alternator positive. The other probe you can touch to clean engine grounding point, anywhere you can get good ground. When engine is running, this again should measure 14V+. MAKE SURE - your positive prove is vell insulated and you do not touch positive probe to the ground, whilst touching the alternator positive terminal, because shorting that will result in blown combination fuse and many other fuses (basically a direct 150A short). Why do this? To confirm that your alternator is still connected properly. Because if alternator is reading 14.4V at the terminals, but under 11V at the Battery then something isn't connected, it may even be blown fuse or something. So it would be good to know this before you start replacing the alternator which may be good.

[Lex_utor]

On 3/15/2024 at 7:31 PM, Linas.P said:

Alternator is dead. Battery probably is simply low, because alternator isn't charging it at all. Did you say it was changed few years ago?

Even if you have dead battery (say 11V) when engine is running you should still get close to 14V, it may be slightly lower since the battery is so dead, but it should never be under 11V. In fact if you battery was under 12 by itself and it drops to under 11 when engine is running, I reckon alternator is not running at all and engine is simply running on battery.

Math here is relatively simple - so let's say maximum charge in the battery is 12.8-12.9V, running the engine requires minimum of 0.3V, so if your alternator is outputting say 13.2V, it would barely charge the battery.

First of all, I suggest you charge the battery again, confirm it is NO LESS than 12.4-12.6V. Start the engine again and if you get less than what you measured before starting the engine  - it is 100% alternator. I am already sure it is alternator, but technically you should not even start measuring it unless battery itself is 12+.

Second thing, you can measure the voltage between alternator plug and body ground. You will see thick positive cable going to alternator and on the alternator there is rubber boot with hole at the top, basically you can stick your positive probe into that hole and that is your alternator positive. The other probe you can touch to clean engine grounding point, anywhere you can get good ground. When engine is running, this again should measure 14V+. MAKE SURE - your positive prove is vell insulated and you do not touch positive probe to the ground, whilst touching the alternator positive terminal, because shorting that will result in blown combination fuse and many other fuses (basically a direct 150A short). Why do this? To confirm that your alternator is still connected properly. Because if alternator is reading 14.4V at the terminals, but under 11V at the battery then something isn't connected, it may even be blown fuse or something. So it would be good to know this before you start replacing the alternator which may be good.

So the autoclub truck was here. I'm a member. He measured it and said it's the alternator. I was today at a couple of places and I think I will have it done with one of them. The alternator they would put in is a Denso. I guess that's is ok?

[H3XME]

1 hour ago, Lex_utor said:

So the autoclub truck was here. I'm a member. He measured it and said it's the alternator. I was today at a couple of places and I think I will have it done with one of them. The alternator they would put in is a Denso. I guess that's is ok?

It's always better to put the exact same one as OEM. Yes they OEM one is Denso but there are different models. Is there any way you could send your alternator off for a rebuild?

[Lex_utor]

18 hours ago, H3XME said:

It's always better to put the exact same one as OEM. Yes they OEM one is Denso but there are different models. Is there any way you could send your alternator off for a rebuild?

The garage mentioned the possibility of "fixing" it if possible. Which would be cheaper. But they said this is not always possible. Plus I guess it would add down time. They will know once they have the car. As for which Denso, they selected the alternator from their computer system using my VIN, so maybe it's the correct Denso?

[Wobbly Legs]

Hi Lex, 

I had exactly the same problem and I was also in a quandary. I couldn't move my car to get it checked for the source of the problem.

I noticed that my Battery terminals were wet. I had had the same Battery on for over 5 years, so I took a chance and ordered a new Battery (Halfords, they offer an installation at your home option for a premium). 

It turned out to be the Battery. 

I experienced the same dying of the Battery, then the next day, I was able to start the car. However, I left it running to warm up, but the Battery light came on. The alternator was giving out about 14 volts (I confirmed this when the Halfords bloke tested it after the new Battery was installed), but because the Battery was Donald Ducked, it wasn't taking the charge. 

Sods Law, though, not long after, I heard a whine coming from under the bonnet. To cut a long story short, it was the alternator. It was still working, but obviously on its way out. Bought a Denso replacement from Autodoc, now everything is fine. 

If it wasn't for the alternator issue, I wouldn't have found out about other issues under the bonnet. All of the following were also Donald Ducked: water pump, idle pulley, tensioner and the serpentine belt. That could have been nasty if not spotted. 

Regards, 

Brian