Ls400 Mk4 Alternator Failure Query

[PEPE]

This is the sequence of events relating to my Mk4 which has done 169,000 miles:

Day 1. I do a 50-mile drive. Car absolutely flawless. Put car in my garage and connect my CTEK Battery charger.

Day 2. The following day I start up the car but I instantly remember Battery is still connected to the CTEK charger. I shut off the engine and disconnect the charger. When I restart the engine the Battery icon in the instrument cluster DOES NOT go off.

Day 3. Alternator failure is diagnosed. Buy new TOYOTA unit (That'll be £219, Sir!). New alternator installed, car performs flawlessly again.

Query: Could I have ruined the alternator by starting the engine whilst the CTEK charger was still connected?

Many thanks in advance for your views.

Pepe

[Malc]

wow, that sounds really unfortunate ....... sorry to hear your news.............. 169k seems a little low mileage for an alternator ( except on a Mk1 and Mk2 where the power steering fluid might have leaked and ruined it )

Malc

[ambermarine]

Pepe

The short answer is yes, starting the car with the charger connected as blown the circuit in the alternator, probably the diodes which are there to convert the ac v produced to dc voltage for Battery charge ,This is produced at a set rate of 14.5 volts for charging which diminishes as the Battery charges up to full capacity. Basically by introducing another component and power source to the circuit you may have created a surge for which there is no protection .

It is unfortunate but just be thankful you did'nt drive out of the garage with it connected.

[goldtop]

Aw nuts. But thanks for the warning.

If it's as ambermarine describes, the diodes would have cost a few quid to replace, plus a bit of labour. Still £219 with Toyota labour included isn't that bad.

Did you get to keep the old one - could be repairable and sellable?

[harrylime]

I have a CTEK charger and thought they were idiot proof (no criticism implied or intended). This must be about the only thing that can go wrong whilst using these. That is very unlucky, but I appreciate the heads up and will take extra care with mine

[ambermarine]

Barry

The diodes are part of the integrated circuitry within the alternator and the nessacary equipment for circuitry testing and references would be required.The alternator can be repaired at specialist companies but individually it is not worth the time or effort unless it is a sophisticated alternator for specialist use, marine is one example.In the main automotive alternators are backloaded( core exchange unit) to aftermarket remanufacturers and re-introduced as rebuilds which is what as been supplied in this instance.

[goldtop]

For sure, if dissassembly and access is difficult, it would be tricky for most DIYers.But I'd rather do any amount of soldering than get oil under my fingernails! ;) And I sit here surrounded by resistors, caps and diodes. No voltage regulators though, but I presume Toyota used readily available parts.

[ambermarine]

Barry

I would imagine that someone with your skills and the correct info on spares would have little trouble repairing an alternator with electrical problems and if I lived next door and mine went south I would be right round knocking on your door.But the mass market deals in quantity and quality sometimes goes out the window as a buddy as just found on his Renault van alt replacement that only lasted two years.

Core replacement units are not as long lasting as original units ,thats why they are half the cost.

[goldtop]

I know what you mean. When I had my old Mercedes, the dealers would say many electronic parts were replace-only, whereas inside they were simple circuits with discrete components - perfectly serviceable by any auto-electrician.

Those were the days... I remember whan it was all fields around here...

[Malc]

...... and when real cars had dynamos

malc

[Colin M]

I have still got a real car with a dynamo - there is one on my Armstrong Siddeley Sapphire 346 and it has performed faultlessly in the 27 years I have owned the car.

I hope I am not tempting fate by writing this ...

[Malc]

well, remembering replacing the brushes on one .................... about 2/6 d I think !!!

Malc

[Mybikes a cx500]

I have a CTEK charger and thought they were idiot proof (no criticism implied or intended). This must be about the only thing that can go wrong whilst using these. That is very unlucky, but I appreciate the heads up and will take extra care with mine

I'm very suprised about this, I can see it if the charger was a dumb old fast charger, but I would not have expected a CTEC to cause any damage, I doubt it could supply much of a maximum current in any event, although it does seem to be to much of a coincidence.

I have a CTEC charger on my motorhome, linked to a solar panel, the car and domestic Battery , so it's entirely possible that the car Battery could be receiving a charge when I start the engine, and that would surely be part of the design of the thing.

[cleverdick]

Reconditioned or not, £219 looks like a steal - especially given that access is so difficult. Not a job I'd want to do, for sure!

Mind you, I once had an alternator fail on a Mk3 Cortina on Christmas Eve. Straight down the breakers, £15 and 20 minutes later - job done! Those were the days...

[messi]

I had an alternator fail on a toyota celsior I had, it was a 1999 mk4, went to breakers yard, got one for £70 Which included fitting

[steve2006]

I actually posed the question of possible damage from starting the car with the unit connected to Ctek and included a link to this post,this is the reply I received.

"Hi

No, if the charger is connected to the Battery and the engine started the charger will see that the voltage drops in the Battery andstart charging the Battery. All of our charger are safe to use, Protects vehicle electronics, ice-free kick, reverse polarity protectedand short circuit proof."

Best regards
Pierre

[ambermarine]

That is a comprehensive answer and to all intents and purposes discounts my theory that there as been a reverse polarity on the alternator using their equipment. The fact is the alternator failed at that instant and I would strongly reccomend that the practice of starting the car with any kind of charger connected is avoided.