[Mk2] [Turbo] Alternator not charging the battery issue!!!!!!!!

[Nellie966]

After head gasket fail, engine rebuild then going for an MOT to be told i need a new battery and alternator
(new battery fitted and i just fitted an alternator today)

I dont get the battery light when i first fire the car up and all electrics seem slow eg windows/wipers/fans.

Looks like its wiring somewhere or fuse?????

what fuse do i check and any pointers.


any advice welcome...
Come on Pete you've helped me out every time before, looking forward to you're response

[Peter Gidden]

OK, you were told you were needed a new alternator - did they test it or just decide it was faulty because it wasn't charging?

The battery warning light gets its +ve feed from the same ignition wire that powers the C.O. relay, so if car starts, that feed will be OK.

The -ve feed to the warning light comes from the alternator itself. When the alternator is charging, the -ve feed is cut by the alternator, extinguishing the light.

To check the warning light unplug the 3 pin plug in the back of the alternator, and run a wire from the yellow wire terminal in the plug to earth. Turn on ignition. If wiring is OK, battery warning light will illuminate.

Sounds as though it's not charging. Have you checked? With engine idling, volts across battery (or anywhere else with +ve feed) should be 13.8-14.2 volts.

If not charging, start by checking fuses ALT SENCING and ECU-IG, both 7.5A.

If OK, unplug 3 pin connector in back of alternator. With ignition on, check for 12+ve at each pin in the loom plug. If all 3 are live, alternator is goosed. If not, wire that is reading incorrectly is bad. Report back if that's the case.

Rev1/2 Turbos have an issue in the loom with the black/yellow wire, but that isn't necessarily your problem.

[Nellie966]

Thanks Pete.
Im guessing they just assumed the alt was shot. Will look into fuses and wires on Saturday. Thanks

[Nellie966]

Hi Peter.
Both the fuses you mentioned are ok, and the battery warning light is ok

(this was checked by putting a wire to the yellow cable and running to earth, warning light came on)

It was noticed that the wires near the alternator plug were a bit worn so they have been replaced and then plugged back in. yet still no battery light on the dash.
The battery is now pretty much flat so its not charging for sure.

ran out of time to check the feeds on the other two cables.
huff huff huff. got to get this bloody car back on the road soon, been working on it for 7 months!! i just want to drive it again.

[Nellie966]

Ok so. all the wires are reading ok. fuses are fine.
When i put a cable from the yellow wire of the plug to the metal work of the throttle body the battery light comes up on the dash.

When i plug the cable in to alt ..... NO light on dash.


What the hell do i do now.

Ps ive been told that the new alt came off of a car and was working fine. i know its no guarantee but i will believe it for now....
What is the know fault with the wire in the loom?

[Peter Gidden]

What is the know fault with the wire in the loom?

If you get 12+ve at all three pins in the 3 pin plug with ignition on, then you have no fault in the loom.

You've shown the dash light and wiring is OK.

IMHO, alterntor goosed.

[Nellie966]

Ok thanks Pete.


Maybe another Alternator on order then, oh well i will just throw more money at it.

Off to dig up the next money tree.

[darkwolf]

I had the same problem with mine for me it was a case of a damaged wire
The wire was black with a yellow strip all I did was and a new wire in from the alternator plug to the fuse box and all worked fine after that

[Peter Gidden]

I had the same problem with mine for me it was a case of a damaged wire
The wire was black with a yellow strip all I did was and a new wire in from the alternator plug to the fuse box and all worked fine after that

Your broken wire is a well known problem on early cars.

In which case, had you done the test on the pins in the 3 pin plug, you'd have got no +ve reading on the black/yellow wire, indicating a wire fault.

OP has done the test and is seeing 12+ve on all 3 wires, so in his case no wires can be broken.

[Draven]

Hi folks

Nellie has asked me to post as he is unable to get on IMOC right now.

There are two other wires not getting a voltage. When we took the engine out we noticed that there was a wire that had been put in that appeared to be using a light bulb type thing as a fuse.

it seems like it might be the broken wire fault that you guys are talking about. In this case which wire do we need to fix and where does it need to go to.?

Which wires to we piggy to. White and red or Blue and yellow?


Thanks

[Peter Gidden]

There are two other wires not getting a voltage. When we took the engine out we noticed that there was a wire that had been put in that appeared to be using a light bulb type thing as a fuse.

it seems like it might be the broken wire fault that you guys are talking about. In this case which wire do we need to fix and where does it need to go to.?

Which wires to we piggy to. White and red or Blue and yellow?

So, just to clarify, with igntion on, he is not getting 12+ve at all 3 pins of the 3 pin plug?

No idea what he is talking about re. light bulbs - dump it.

The wiring is quite simple:

1) Yellow - to battery warning light in dash
2) White/Red - to "Alt Sencing" fuse.
3) Black/Yellow to "ECU-IG" fuse.

I have only ever had to bypass the black/yellow wire.

[Draven]

Have passed the info on Pete

I'd have a look myself but am currently at work.


On the lightbulb thing. I was confused what it was there for but yeah we've already binned it.

[Draven]

Right he says he's done as you've advised Pete the alternator is now charging the battery but the dash light stays on..

Any ideas?

[Peter Gidden]

Right he says he's done as you've advised Pete the alternator is now charging the battery but the dash light stays on..

Any ideas?

If the battery light is on permanently, and wiring is correct, and alternator is charging, alternator must be goosed.

[Draven]

I'm confused how it can be bu88ered if it is charging..

[Nellie966]

Ok, so the battery is charging and is now showing 14-14.5v whilst engine idle.

However i now get these lights come up on the dash (hope this link works)
http://www.imoc.co.uk/forums/viewtopic.php?t=133051
i dont get the seat belt one though.


any ideas, is it the alternator regulator??????
if so, i think i will put my original alt back on and try that.
Although i have been assured from mr2mithch that the 2nd hand alt from him is fine.

[racingdrivermatt]

Hi all,

So I got the three usual lights on my dash all of a sudden, You know the ones...cat, battery, and engine cooling fan etc.

So I checked my battery after getting home, it gave me a reading of 11.5v (down I know),

So I took the plug off the alternator and here's what readings I get...

10.6v yellow wire
11.3v black/yellow stripe wire
11.3v white/red wire

I personally think the battery is ok, it's fairly recent, the belts were changed last year also, and I had noises around the alternator area so figure it's shot, not forgetting to mention a crack on it's casing. Here's the thing though,

The alternator output gives a reading of 11.5v, so does this suggest it is charging but not at the right rate? I'm unsure whether this could be wiring or alternator or both!

Help greatly appreciated!!!

[Peter Gidden]

Hi all,

So I got the three usual lights on my dash all of a sudden, You know the ones...cat, battery, and engine cooling fan etc.

So I checked my battery after getting home, it gave me a reading of 11.5v (down I know),

So I took the plug off the alternator and here's what readings I get...

10.6v yellow wire
11.3v black/yellow stripe wire
11.3v white/red wire

I personally think the battery is ok, it's fairly recent, the belts were changed last year also, and I had noises around the alternator area so figure it's shot, not forgetting to mention a crack on it's casing. Here's the thing though,

The alternator output gives a reading of 11.5v, so does this suggest it is charging but not at the right rate? I'm unsure whether this could be wiring or alternator or both!

Help greatly appreciated!!!

Alternator is doing nothing - you're seeing battery voltage. Change alternator.

[racingdrivermatt]

Ok I struggled til 10pm getting the damn thing out (bu88er of a job on the turbo models I have to say), and joy of joys, the sticky label only reveals the last three numbers of a code ...060!

Does anyone have any clue what alternator I'd need, going off only those three digits? Most parts places can't pull my car up on the system with it being an import etc.

The car has power steering as well as I've heard this makes a difference to the alternator required?

Help very much appreciated!!

Matt.

[Peter Gidden]

Does anyone have any clue what alternator I'd need.

You don't need part numbers etc.

You just need (assuming you have a turbo), a turbo alternator with either an oval or round plug, to match your loom. Simples.