Battery Warning Light On - Belt Ok And Battery Charging.

[Badger1966]

Hi all,

Yet more problems with my is220. Love the car but it has more issues than than I can shake a stick at! Any way, the latest problem is the Battery light came on the dash this morning. Auxiliary belt seems ok and is turning with the engine. Battery is charging at around 13.3 volts at 2000rpm. Please, has any one got any ideas?

Thank you

[madasahatter]

Battery or Alternator when that light comes on.

[Badger1966]

Battery is reading 12.3v at the moment after 4 hours since I got to work. It appears to be original Battery but not 100% sure.

[Badger1966]

Battery or Alternator when that light comes on.

And yes, I would also assume Battery or alternator (or belt) But Alternator is charging, belt is turning and doesn't appear to be slipping (no high pitched squealing noise) Battery seems to be holding charge. I am lost.

[madasahatter]

Does it have a clear window on shine a torch down red is good i believe. Its the left hand corner on Battery.

[Badger1966]

Does it have a clear window on shine a torch down red is good i believe. Its the left hand corner on battery.

Just checked, and no, my Battery does not have a little check window thing. And Green is good, Red or nothing is bad. ( I used to sell Car and Motorcycle batteries ) I wonder if the Battery is at a threshold of failure and the car senses this despite the signs that all is well?

[johnatg]

Get the Battery checked with a proper tester, but I'm afraid it's more likely that the alternator has failed. 13.3v is nowhere near enough - it should be charging at 14.2 volts or so. It's just possible that the Battery is pulling it down but not likely.

It's most likely that a diode has failed - this can be caused by poor Battery connections, a poor (corroded?) earth or accidentally disconnecting the Battery whilst the engine is running. Or welding with the alternator connected.

[Badger1966]

Get the battery checked with a proper tester, but I'm afraid it's more likely that the alternator has failed. 13.3v is nowhere near enough - it should be charging at 14.2 volts or so. It's just possible that the battery is pulling it down but not likely.

It's most likely that a diode has failed - this can be caused by poor battery connections, a poor (corroded?) earth or accidentally disconnecting the battery whilst the engine is running. Or welding with the alternator connected.

Hellooo, You kind of read my mind with the volts. Thought it should be 14 + volts. Battery connections are all good and tight, and even greased. Never disconnected while running and never had any welding. I'm waiting for a call as we speak from Lexus to see what they will charge to supply and fit. I imagine it will be horrific

[normski2]

Can Battery chargers cause a diode failure?

I was LED to believe this was the case....so I've always disconnected both clamps whenever I've had to charge a Battery.

It's usually the wifes MX5 after we've come back from hols!

John...you've made a good point about the earth strap. I know the earth to body strap connection has been an issue for some 220/250's

[Badger1966]

As I suspected, horrific. Lexus want £447.12 I could cry as I just paid my insurance yesterday. It never rains......

[Badger1966]

As I suspected, horrific. Lexus want £447.12 I could cry as I just paid my insurance yesterday. It never rains...

[Badger1966]

Cant do anything now until Friday. I will check all connections then. Thanks everyone!

[Verbout]

Sounds like alternator trouble as John says, the reading should be well over 14 volts with the engine at 2000 rpm.

View this video on how to test the alternator, you will need a multimeter.

https://m.youtube.com/watch?v=LGB6ZEjGm7Q

[Badger1966]

Sounds like alternator trouble as John says, the reading should be well over 14 volts with the engine at 2000 rpm.

View this video on how to test the alternator, you will need a multimeter.

Thanks, do you have a link for the video?

[Verbout]

Sounds like alternator trouble as John says, the reading should be well over 14 volts with the engine at 2000 rpm.

View this video on how to test the alternator, you will need a multimeter.

Thanks, do you have a link for the video?

My apologies, trying to do several jobs at once and making a c**k of each one.

https://m.youtube.com/watch?v=LGB6ZEjGm7Q

[Badger1966]

Lol, no worries :D Video was great! Thank you so much. I did the basic test of checking the charge already. I will do all the other checks on Friday as that's my day off to be sure it's not just a bad connection some ware. Fingers crossed the car will keep working until then.

Thanks again!

[Badger1966]

On another note, as Lexus only charge an hours labour to change the alternator, I will tackle the job myself. Has anyone had any experience changing the alternator on an IS220d?

[Verbout]

I have changed quite a few alternators, not on a Lexus though, and I would not expect to do so just yet:lol:

The only issue I have found with changing alternators is the degree of access. It's only nuts bolts and belts with an electrical connection, but getting to some alternators and their fastenings is sometimes a pig.

[Badger1966]

Well mine has just under 140k miles. I guess things don't last forever! And indeed access can be a problem on some cars. Sometimes easier to take the engine out!. The last one I did was on a Rover 75 diesel. Had to get to it from underneath and took all sorts off to get to it. Luckily the access looks very good on the 220. I was just wondering if it was as straight forward as it looks? Or if anyone had any hints or tips?

[Badger1966]

Hello all.

Quick update. I had epic alternator failure today. Literally smoking! and terrible smell. The good news is that it happened out side the shop that I went to, to get the alternator! And also luckily for me they also fit them. Hopefully all fixed tomorrow. It went from light on the dash to self destruct in less than 50 miles! I will let you know how I get on tomorrow.

[is200 Newbie]

How lucky was that !!

[Verbout]

Interested in the update.

[Badger1966]

Hello all,

Well all sorted now, cars running as well as it did before. It cost £250 fitted, including vat. And it was a brand new alternator, not recon. They also charged my Battery overnight for me. Nice people. They also noticed some loose fasteners on the air box which they tightened up. Nice to find somewhere that pays attention!

If only I could sort the cars amazing ability to chuck large amounts of smoke out the exhaust from time to time, And also sort it going into limp mode every other day I will be a happy man!!! LOL.

[Badger1966]

How lucky was that !!

Very lucky indeed! probably more chance of winning the lottery, lol. I literally saw the shop but was on the wrong side of the road. So I stopped with my right indicator on. A space came but when I pulled away the power steering had gone. Quite a shock trying to turn and the wheel wouldn't move. But managed to force it, So I pull up outside the shop, leave it running and go inside. Probably 2 mins later I went back to the car with the guy from the shop and then cough and splutter, the engine died. Lifted the bonnet to see smoke and a terrible smell. And that was that. dead alternator and flat Battery. Really was a minor miracle as I had just driven 23 miles and was just passing the shop on my way back to work.