On my way to Stirling this moring, taking the other half to uni, my alternator light came on, so thought, oh bugger, bet my alternator has just gone (was overtaking, revs quite high 5500-6000 and beep, alternator light :(

so as i waited for her to finish uni on, i forgot and played radio etc, started car two hours later to be greated by the light and the engine doing what can only be described as 'hunting' which i'm guessing is low voltage in the battery, could anything else cause this or has my alternator passed it??

Does anyone have an alternator for a 1.4 16v fabia kicking about?? or is there someone who can recon it around stirling/glasgow for a decent price £170 for new one, £55 for second hand one

cheers

stewart

New question.....

Where does the sense wire go, I looked at it today, followed it from alternator (plug) two wire (brown & blue wires) down to plug at gearbox, again, just two wires at plug (again brown & blue) and then up to bunch of wires which run up and disappear under the battery tray...

Is it the plug that breaks, everything seems fine and intact, do I just chop out the gearbox plug and crimp or solder the two ends?? Last time I checked it was giving out almost 14v but the Barrett wasn't taking a charge, read on here it's the sense wire that causes this!! Really bugging me not having a car, that's been two weeks now :-(

Edited 7 December, 201015 yr by Waky

Check the alternator regulator brush length before you change the whole alternator . It could be a short brush with very little spring presure that is the fault . A new regulator (including the brushes) is only about £20.

Also check alternator sense wire at the connector on the front of the gearbox. Very common for it to break.

Also check alternator sense wire at the connector on the front of the gearbox. Very common for it to break.

Cheers bud, will check that!! Was just the way I was accelerating quite fast, and whilst rising up through the revs it went, but I'll check this sense wire!! You got a photo of where it is, does it go from battery to box, alt to box or is it one of these ones from that stupid battery tray thing above the battery??

Are the brushes available for my alternator??

Cheers

Stewart

Cheers bud, will check that!! Was just the way I was accelerating quite fast, and whilst rising up through the revs it went, but I'll check this sense wire!! You got a photo of where it is, does it go from battery to box, alt to box or is it one of these ones from that stupid battery tray thing above the battery??

Are the brushes available for my alternator?? Cheers Stewart

Now I could be wrong here, but I reckon that you said that your car has a 1.4 16V engine, ie petrol - so I'm guessing that the broken sense wire will not be the problem - I thought that the broken wires was more a TDi engined car problem. If you look down from under the (open) bonnet you should see well down near the gearbox/engine "joint" some connectors - I seem to remember that one is the manu-cat Lambda probe connection and one is the alternator sense/load wire connection - just check that here are no tight or broken wires to that junction. Maybe look for indepth info using the search function as there will be pictures on this site. I would think that there will be OEM or aftermarket regulator/brush box for that alternator - but once again you will need to get in about the car to find out its exact manufacturer and type by reading off what is currently fitted.

One thing, do you think that the batery is still getting charged? If it is getting charged then I'd guess that there is a wiring fault keeping that light on or the alternator's "charge indicator" circuit is faulty - once again changing the regulator/brush box pack should fix that. Point is,a petrol engine needs quite a bit of electrical power to keep it going, so I'd guess a battery that is not getting charged would not support engine running for too long.

The next issue could be a blown or broken diode in the rectifying stack - that would cause under charging and that would aslo bring the warning light on - maybe get your volt meter and current clamp out - or take it to someone that has the right tools.

Edited 21 November, 201015 yr by rum4mo

hi bud,

cheers for the reply, you weren't out last night lol...

I'm going to go check the car out tomorrow, take up a voltmeter and see whats the score, i don't think it was charging, thats why it was almost hunting when i tried it later on. If it is broken, i'm going to whip it off and see if skoda or anyone do a replacement brush kit...

one thing though, where and what is the diode, part of the alternator?? that what regulates the power coming out of alternator??

cheers again,

Stewart

hi bud,

cheers for the reply, you weren't out last night lol...

I'm going to go check the car out tomorrow, take up a voltmeter and see whats the score, i don't think it was charging, thats why it was almost hunting when i tried it later on. If it is broken, i'm going to whip it off and see if skoda or anyone do a replacement brush kit...

one thing though, where and what is the diode, part of the alternator?? that what regulates the power coming out of alternator??

cheers again, Stewart

I think that the diode pack will probably be a circular "slice" at the back of the alternator body, the regulator and brush box will normally get mounted externally on the rear of that. I seem to remember that alternators are 3 phase devices so there will be a six connected to the three windings - so prepare to unsolder a few heavy leads to you are going to test the diode stack (or pack).

It's more than likely the sensor wire thingy, Many a 1.4 petrol Ibiza Fabia and Polo are affected. Sometimes the wire breaks inside the insulation and is not obvious just looking at it.

Car was charging fine, across the battery i got 13.64v, but later on that night i drove home with the lights on and by the time i got home (10 miles) the battery was dead...

Also i have no sidelights now, both fuses and bulbs are good :wonder:

I'm plugging it into vagcom tomorrow to see what pops up

Bumpy with new question top!.?,'

Anyone??

The DFM wire goes to the engine ECU, if its faulty your battery light wont come on with the ignition.