Car won't start - ideas/help... ***UPDATE - STILL FUBARRED!!***

[KarlBristol]

I'm guessing - get an ammeter that I know works and fit across the negative battery terminal and disconnected live wires for the car. Then unplug the alternator and see if the drain goes on the multimeter.

If it doesn't drop I presume that I pull out every fuse in the car one at a time to locate the potential issue.


Guess I'm running the 11 miles to work and 11 miles home until I get the issue fixed

[tottacrolla]

A couple of minutes searching for "alternator draining battery"
revealed this:
http://forums.anandtech.com/showthread.php?t=2254082

Plenty of info on the other search results too.

[Peter Gidden]

I'm guessing - get an ammeter that I know works and fit across the negative battery terminal and disconnected live wires for the car. Then unplug the alternator and see if the drain goes on the multimeter.

If it doesn't drop I presume that I pull out every fuse in the car one at a time to locate the potential issue.

Good plan. But i suspect it'll be the alternator. Diode pack goes down. Had 3 or 4 in the workshop over the years with exact same problem.

[KarlBristol]

Is that an entire alternator replacement then or can the alternator be stripped down and repaired?

[Peter Gidden]

Is that an entire alternator replacement then or can the alternator be stripped down and repaired?

A competent alternator specialist should be able to repair it.

[KarlBristol]

I tried my multimeter on something else this evening and it worked fine but still reads 0 on the car. It turns out that someone else that I know had a similar issue with their multimeter but they used an analog one and it worked fine.

I will try to source an analogue multimeter now to do the tests I need.

I do suspect from some online research that the car will require a new alternator.... Which is probably easier said than done with this engine set up

The main issue I've experienced so far is that I can't source an alternator even if that is the issue. Nowhere seems to have one, GSF, Eurocarparts, etc... I don't really want to be ripped off by Lexus. Can anyone suggest where I can get hold of an alternator?

[thomp1983]

If you take yours to a specialist they'll probably fix it in a day

Chris

[Peter Gidden]

I tried my multimeter on something else this evening and it worked fine but still reads 0 on the car. It turns out that someone else that I know had a similar issue with their multimeter but they used an analog one and it worked fine.

Any digital ammeter will work fine on a car. Depending on the number of digits and the ranges available, you may have to reduce the range until you get a reading.

The main issue I've experienced so far is that I can't source an alternator even if that is the issue. Nowhere seems to have one, GSF, Eurocarparts, etc... I don't really want to be ripped off by Lexus. Can anyone suggest where I can get hold of an alternator?

Your local alternator specialist should be able to recondition it without a problem.

[KarlBristol]

The main issue I've experienced so far is that I can't source an alternator even if that is the issue. Nowhere seems to have one, GSF, Eurocarparts, etc... I don't really want to be ripped off by Lexus. Can anyone suggest where I can get hold of an alternator?

Your local alternator specialist should be able to recondition it without a problem.

If I do some tests and find that the alternator is the issue I wouldn't want the diodes repaired in it just for something else to break in it a couple of months down the line... Knowing my luck the alternator would become a reoccurring issue.

It's probably original which means it's over 10 years old and therefore more prone to failure. If I'm spending money on it I'd rather replace it all together than get it repaired.



I have just found this link from the states which has a Denso one for £147.36 delivered. I'd prefer to buy a UK based one but if there isn't one here I will import one...

http://www.ebay.co.uk/itm/NEW-ALTERNATO ... 1c370bc1cb

[Peter Gidden]

The main issue I've experienced so far is that I can't source an alternator even if that is the issue. Nowhere seems to have one, GSF, Eurocarparts, etc... I don't really want to be ripped off by Lexus. Can anyone suggest where I can get hold of an alternator?

Your local alternator specialist should be able to recondition it without a problem.

If I do some tests and find that the alternator is the issue I wouldn't want the diodes repaired in it just for something else to break in it a couple of months down the line... Knowing my luck the alternator would become a reoccurring issue.

It's probably original which means it's over 10 years old and therefore more prone to failure. If I'm spending money on it I'd rather replace it all together than get it repaired.

I agree totally. Which is why i suggested having it reconditioned. Reconditioning is not the same as repairing. Which is why the guarantees are longer, in the case of my guy, 2 years.

[KarlBristol]

Update - managed to buy a new multimeter tonight and ran it in line with the battery, it measured 0.28A which is significant drain on the battery.

Unplugged every fuse hoping it was one of them. It wasn't.

Eventually I plucked up the courage to unplug my alternator and try it again. The reading dropped from 0.28 to 0.00/0.01

Pleased that the issue is located but not ecstatic about what's wrong
Going to order a new alternator tonight

[Peter Gidden]

Update - managed to buy a new multimeter tonight and ran it in line with the battery, it measured 0.28A which is significant drain on the battery.

Unplugged every fuse hoping it was one of them. It wasn't.

Eventually I plucked up the courage to unplug my alternator and try it again. The reading dropped from 0.28 to 0.00/0.01

Ha! Just as we discussed on the phone!

And dump your old voltmeter!

Glad you sorted it.

[KarlBristol]

Old multimeter has now been binned and I've got an all singing all dancing one

Damn alternator

At least it's an easy home job - the issue will be the amount of room available to try and remove it against the firewall without lifting the engine out

[KarlBristol]

UPDATE....

Well the brand new alternator was bought, delivered and fitted under the belief that the old one had been drawing current from the system. The car was run for 10 miles with the new alternator in and then tested. This was now only showing a drain of 0.014A as opposed to the old 0.278A

Problem solved
Or so I thought....


Car was laid up for x2 days and then today I went to start it and it wouldn't... I had a flat battery. I replaced it with a fully charged battery and did an inline Amp test to test for electrical draw again. Showed a reading of 0.37A

Unplugged the alternator and this dropped to 0.014A, so again I presume that the diodes were fubared. Did a diode test on both alternators and both alternators are perfectly healthy. Did all the usual tests and both the old and new alternator are throwing out the correct voltage, charging the battery, etc...

There's clearly an issue in between the battery and alternator
I'm pretty sure it isn't the alternator itself and both are more than healthy (he says after throwing away hundreds on a new alternator!!)

Ideas??!!

[KarlBristol]

Just re-tried it, and it's showing a drain of 0.41A
It's reading this on both the positive and negative terminals if that means anything.

I can only think that it might be a wire shorting out between the battery and the alternator, it's definitely not an earthing issue.

Bit stuck now without more internet research. Any ideas anyone??

Car is still unusable

[ashley]

Maybe irrelevant, but are you sure it's not you imobiliser?

[KarlBristol]

Maybe irrelevant, but are you sure it's not you imobiliser?

When the alternator is unplugged the electrical draw is only 0.014A so Im pretty sure it's not the immobiliser.

I'm thinking it's based more around the alternator/battery wiring... Somewhere lol.

[Peter Gidden]

I can only think that it might be a wire shorting out between the battery and the alternator

There can't be. And you've proved it.

If there was a wiring fault between battery and alternator, it would still be present when you disconnected the alternator.

There should be no current flow theough the alternator when the electrics are switched off.

[KarlBristol]

Thoughts??

The diodes are fine in both alternators, and following tests today on both alternators they both turn out to be very healthy units. It's not the alternator at fault... There's something else going on.

[Peter Gidden]

Thoughts??

The diodes are fine in both alternators, and following tests today on both alternators they both turn out to be very healthy units. It's not the alternator at fault... There's something else going on.

OK, do me a favour.

Leave main alternator lead connected, but pull out 3 pin plug.