Battery warning light on permanently

Hi guys,

The battery warning light is on pretty much all the time on my '89 cabby gti.  It does go off occasionally but never for long. I had it looked at when the car was at the garage but the battery is apparently a1 so the fault lies somewhere else.  Anyone got any ideas where I should be looking?

Cheers,
Euan

you need to check the alternator is charging the battery and make sure the blue wire is intact

Thanks for the tip. If the alternator wasn't charging the battery how long would it last? I had the car out for a run of about 80 miles today and it was perfect apart from the battery light. If the alternator wasn't charging properly it wouldn't last for as long a drive as that or would it?

What does the blue wire do? I'm not sure where it is but I'll have a look for it tomorrow.

Cheers,
Euan

Mate check the earth on the Rocker cover, if your alternator wasnt working, you wouldnt  do 80 miles, Im not an expert but..

Cheers baggie, will have a look at the earth and see whats what. Update to follow….

Euan

I only know army vehicles mate, but give the  rocker cover a good clean and all attached cables and see, its not you alternator, do you know hao to check alternator?

Not a clue mate. I'm a beginner with all this. I'm relying on my Haynes manual, you tube and this website to get advice and info. Hoping to learn as I do bits and pieces.
All advice is greatly appreciated!

Euan

remove the brush pack from the rear of the alternator, check the condition of brushes. also look at the 2 metal contact points to ensure they're clean. 1 is around a screw head, the other touches a metal prong inside the hole

Did as you suggested John and think you might be on to something with the brushes. Mine are well worn and the visible part measures only 7-8mm. The Haynes manual says that anything less than 15mm means they should be replaced.

Having trouble finding brushes to fit the regulator. Phoned 3 places today. 2 can't source for the particular model of Bosch alternator on my cabby gti and the other place took the details and said they'll let me know if they can get them.

Have found somewhere that stocks the whole regulator unit for my alternator so may just buy that if no joy with the brushes.

Also checked the wires and connections today. All seem fine. Thanks for the help up to now guys.

UPDATE: Sourced new brushes which arrived today so I borrowed a soldering iron and got cracking. Changed the brushes without too much trouble and refitted the regulator to the alternator and reconnected the battery.Fired up the engine and…….the battery light came on straight away. Problem not solved unfortunately.

Any other suggestions guys?

How come you didn't change the whole regulator? you can get them for about a tenner off ebay. Could be a diode problem rather than bushes. Ebay

When I saw how worn the bushes were I assumed that was the problem but yeah I think it might be worth trying a new regulator in there. Will re-check all connections 2moro just in case…..

Cheers,
Euan

Update: Fitted a new voltage regulator this morning but battery light is still on. Anyone got any other suggestions? Have checked the connections and all seem ok.

Cheers,
Euan

Blue exciter wire from the alternator.
Is that properly connected?

Will check tomorrow. Where on the alternator should I look?

Ta,
Euan

im thinking alternator is duff. the blue wire should run from the alternator pin D+ across to the blue wire spade near the battery +ve. try disconnecting the spade to see if the light goes out, if it does the wire is ok from the clocks to the spade at least.

trace it from there carefully, make sure its not earthed anywhere, and it is run to the D+ terminal on the alternator not to one of the other random studs

Ok, I've had a good look around and checked what John suggested. I removed the alternator wiring loom and even replaced the blue wire and connectors with new stuff just in case there was a fault somewhere I hadn't seen. When hooked back up it was same as before, the battery light came straight on when car was started.

Thats me now tried a new regulator, new blue wire and its connectors. All connections seem ok. If the alternator was dud then the car wouldn't be able to drive far but I've had
it on a couple of decent journeys lately with no problems.

Any suggestions welcome!

I have had all sorts of issues on my clocks and it was all down to the connector on the clock not contacting properly on the wire loom connectors.

I took mine out and gave the contacts on the blue ribbon a clean, then put a couple of turns of insulating tape over the plastic bit, then dropped the blue ribbon over and re connected.
The tape just bulks out so the contacts are fully touching.

Thanks Chortle, may well be worth a look at the clocks. A job for tomorrow me thinks.

Any other suggestions are welcome!

Also while I'm begging for help, anyone got a suggestion on the easiest way to get the interior light wires down to the switch at the drivers door. My wiring was missing on the drivers side so I've got a new wire and connectors ready but it won't feed through! Tried pushing thick strimmer wire along the cavity above the windscreen to act as a guide but it gets stuck at the corner of the windscreen. Played about with it for over an hour. Don't really want to have to start taking the car apart if possible! Anyone got experience of doing this?

Cheers,
Euan

I had simliar, the auto leccy fed it through the side and up through the vynil trim on the A pillars to the light.
The wire wasn't that visible to be honest.