Full proof guide to testing T27 2.0 diesel alternator

[SAM LOVERS HER TOYOTAS]

Hi,

My hubby has never had an issue with starting his 2010 t27 2.0 diesel since ownership in 2016, until we ran a hardwired Dashcam last year sometime which has since been removed as we assumed that was draining the Battery. We had the Battery replaced by toyota. But the vehicle continues to drain the Battery. Jump starting and letting the car run for an hour used to start up again after a few days. Now it's dead the very next day. We now think it could be a bad alternator. Admittedly he hardly drives it.

If anybody is willing to provide a step guide to testing the battery and alternator to diagnose what needs replacing, would be much appreciated greatly! The weather is much colder and the avensis is a back up if my aygo becomes unusable for whatever reason. 

Any help would be greatly appreciated. Thank you.

[SAM LOVERS HER TOYOTAS]

P.s

We have a yellow multimeter but little experience with using it. I assume one plugs the red lead in positive and black in negative and sets the dial to 20v.

That's as far as I think we go sadly.

[Stivino]

https://m.wikihow.com/Check-an-Alternator

[SAM LOVERS HER TOYOTAS]

Morning All...

Sitting in the Avensis right now, sadly cant use our multimeter as noticed the cover to replace batteries has rusty screws hence cant open the cover... so that's that.

But using our ring automotive Battery tester plugged into the cigarette lighter...after jump starting the vehicle...we have noted the following readings:

PRE JUMP START: start stop button
1st click...11.1v
2nd click 10.6...10.9v

POST JUMP START: car running all accessories off!
13.8 TO 14.1 to 14.2v

Heating on 13.7 to 13.9v
Radio on same as above
Lights on 13.4 to 13.7v
Ac on 13.5 to 13.8v
Heated seats 13.6 to 13.9v

Where yet to decide which Avenue to take...

Is it the Battery?

is it the alternator?

Is it a fuse between Battery & alternator? Found that out via a google search reading through forums

I dont think it's a starter motor issue...or the start stop button...random ideas being thrown here maybe totally unrelated!

[mrfixer]

The alternator should put out 13.5-14.4V at 2000rpm depending on the state of charge of your battery and the electrical load.

Looking at your readings I suspect your Battery is going bad.  Batteries don't like to sit unused or short journey use.  Replace with a new branded and warranted Battery (Bosch, Varta, Yuasa). Be careful to check dimensions before purchase because there are several different sizes.  Make sure the terminals are clean and apply a bit of Battery grease (or copper grease etc) to stop corrosion. Also check the condition of the earthing strap where it bolts to the bodywork.

[Stivino]

In his first post, he states that the Battery was replaced by Toyota.

[mrfixer]

21 minutes ago, Stivino said:

In his first post, he states that the battery was replaced by Toyota.

Ok. I am not clear how old the Battery is...

If the Battery is less than a couple of years old and in good condition then either the car is being left a long time (several weeks) without use or there is a circuit draining the Battery.

To check for battery drain you should monitor the battery current after having switched the car off for at least 15 minutes. Use a a multimeter or (preferably) clip-on DC ammeter. You should see no more than about 50mA (0.050A) quiescent current drain. If you observe more than this then you have an active circuit. Remove fuses in turn and watch the current draw until you locate the active circuit. Favourite culprits are aftermarket accessories, boot/glovebox lights and leaky alternators.

If the quiescent current consumption is less than about 50mA then you are back to a bad battery. If not using the car for more than about three weeks then I would disconnect the battery neg. terminal.

[SAM LOVERS HER TOYOTAS]

4 hours ago, mrfixer said:

Ok. I am not clear how old the battery is...

If the battery is less than a couple of years old and in good condition then either the car is being left a long time (several weeks) without use or there is a circuit draining the battery.

To check for battery drain you should monitor the battery current after having switched the car off for at least 15 minutes. Use a a multimeter or (preferably) clip-on DC ammeter. You should see no more than about 50mA (0.050A) quiescent current drain. If you observe more than this then you have an active circuit. Remove fuses in turn and watch the current draw until you locate the active circuit. Favourite culprits are aftermarket accessories, boot/glovebox lights and leaky alternators.

If the quiescent current consumption is less than about 50mA then you are back to a bad battery. If not using the car for more than about three weeks then I would disconnect the battery neg. terminal.

When you say remove fuses...do you mean each and every fuse cabin side and engine bay? 

Am I looking for a blown fuse then?

How do I test the alternator itself just to rule that out? 

Spoke with a toyota tech at my dealership this morning, known him for years, who replied exactly as you just did I.e non use can deplete Battery or an active circuit some where but where? All started after that hard wire dash cam install...but that's been stripped out and original fuses replaced. He mentioned an online fuse between alternator and Battery but if that had blown it would trigger a dash light but there isnt one

[SAM LOVERS HER TOYOTAS]

It's been 6hrs since jumping her to start this morning, I'll pop back out to see if she fires up by herself again...never did like push start stop buttons! Makes me nervous! And when it doesnt want to start up and all the lights go funny it's so scary

[mrfixer]

You are measuring correct alternator voltage at your cig. lighter so the big fuse between Battery and alternator is OK.

To check for spurious current draw you need to monitor the current being drawn from your Battery with everything turned off. It shouldn't be more than about 0.050A (50mA).

Let's say its 200mA - so you have a fault.  Remove a fuse - if the current doesn't change then its not that particular circuit. So replace that fuse and remove the next fuse in turn.  When you eventually remove a fuse and the current drops to 50mA then you have found your faulty circuit and can investigate further.

To check for a leaky alternator CAREFULLY remove the thick output cable from the back of the alternator and check the Battery current. Do not let this cable terminal touch any bare metal otherwise you'll get a shower of sparks and blow the big fuse.

Be aware that frequent starting of the car and then not driving it (e.g. shunting cars around a yard every day) will soon see off a battery. That's why all car dealers have jump-start packs.

[SAM LOVERS HER TOYOTAS]

2 hours ago, mrfixer said:

You are measuring correct alternator voltage at your cig. lighter so the big fuse between battery and alternator is OK.

To check for spurious current draw you need to monitor the current being drawn from your battery with everything turned off. It shouldn't be more than about 0.050A (50mA).

Let's say its 200mA - so you have a fault.  Remove a fuse - if the current doesn't change then its not that particular circuit. So replace that fuse and remove the next fuse in turn.  When you eventually remove a fuse and the current drops to 50mA then you have found your faulty circuit and can investigate further.

To check for a leaky alternator CAREFULLY remove the thick output cable from the back of the alternator and check the battery current. Do not let this cable terminal touch any bare metal otherwise you'll get a shower of sparks and blow the big fuse.

Be aware that frequent starting of the car and then not driving it (e.g. shunting cars around a yard every day) will soon see off a battery. That's why all car dealers have jump-start packs.

All making sense to me now, amazing, i am online as we speak looking for a new multimeter so that I can get to work with this fuse route option. I will report back any findings, thank you, much appreciated x

[Edward Tomskii]

 Frequent short journeys do not assist complete renewal of accumulator. If you tell about beginning this disrepair after setting of additional recorder, then the wires of the power of this recorder module are not correctly connected maybe. I would clean everything in general from motor-car wires, insulated them, and toga measured the current of consumption. Successes!