hello,

as the topic suggests about 5 miles ago i noticed the battery light was on. the idle speed has risen by about 80rpm (from about 900 to a smidge under 1000rpm. the alternator belt hasn't fallen off and appears to still be tensioned properly. the alternator multiplug is clean and all the visible wiring appears in good order. all the battery fuses are intact.

given the idle speed has gone up (less engine load?) do i take it the alternator is knackered? there have been no symptoms and a weird green mark/light contraption on the battery is still green.

any advise appreciated,

regards

toby

hi when mates light came on his bora it was the alitornater....but get it tested....

hi,

where do you get them tested? a mobile auto electrician? or can normal garages do the work?

hi,

where do you get them tested? a mobile auto electrician? or can normal garages do the work?

any garage buddy..

ah, thanks for that.

next question - does the the tensioner just pull back in order to de-tension the belt? it looks like there are two holes that i hope once aligned can be pinned to allow the belt to be replaced (which i may as well do if the alternator is coming out). its a 1.6 engine.

cheers

get the alternator output checked before you throw money at it, simple enough to do

hello,

as the topic suggests about 5 miles ago i noticed the battery light was on. the idle speed has risen by about 80rpm (from about 900 to a smidge under 1000rpm. the alternator belt hasn't fallen off and appears to still be tensioned properly. the alternator multiplug is clean and all the visible wiring appears in good order. all the battery fuses are intact.

given the idle speed has gone up (less engine load?) do i take it the alternator is knackered? there have been no symptoms and a weird green mark/light contraption on the battery is still green.

any advise appreciated,

regards

toby

Hi Toby

Whats your location, I have the test gear

Radiotwo

Get yourself a multimeter, put it on the battery, if 14volts being produced id be inclined to say the alternator is okay, put on all lights and electrical items in the car, if it drops to 13.5 volts its okay and then you rev engine and goes to 14v again then it would be fine in my opinion.

If it stays at 12v or lower then its not charging.

Hi RadioTwo - i'm just outside portsmouth so i think thats a little out of your way - thanks for the offer though.

hi also Agent47C2000 - i'm going to check the alternator output with a multimeter a little later - i need someone to rev the car to 2000 revs or so to get the unit up to max output whilst i check the readings.

i've played with the tensioner earlier and apart from threading a new belt on (air-con makes this look like fun....) replacing the unit (should it come to that) doesn't look too bad.

as all the regulators and diodes and gubbins appear to be on the alternator itself if its one of these bits rather than duff coils inside how would this change things if they (the diodes and suchlike) are faulty? there doesn't seem to be anything else to go wrong other than the thick cable running to the battery which i'll check for resistance whilst i'm there. the battery appears to be ok as it starts the car fine and at the moment i think is running the car ok.

thanks for all input,

regards

toby

Hi RadioTwo - i'm just outside portsmouth so i think thats a little out of your way - thanks for the offer though.

hi also Agent47C2000 - i'm going to check the alternator output with a multimeter a little later - i need someone to rev the car to 2000 revs or so to get the unit up to max output whilst i check the readings.

i've played with the tensioner earlier and apart from threading a new belt on (air-con makes this look like fun....) replacing the unit (should it come to that) doesn't look too bad.

as all the regulators and diodes and gubbins appear to be on the alternator itself if its one of these bits rather than duff coils inside how would this change things if they (the diodes and suchlike) are faulty? there doesn't seem to be anything else to go wrong other than the thick cable running to the battery which i'll check for resistance whilst i'm there. the battery appears to be ok as it starts the car fine and at the moment i think is running the car ok.

thanks for all input,

regards

toby

Hi Again Toby

Actually that was a hint to add to your profile, so if any one has the test gear etc they know where you are !

Any way back to the charging etc, and this was not the same symptoms as yours, but my son-in-law has just had a problem with his 1.9TDi and I did a check on it, and when checking the voltage output (just over tickover 2000rpm) we were getting 13.2 Volts, and no more, I happened to touch the nut on the main connection on the alternator and it was hot, I got a spanner and found it loose(it was finger tight, but very loose with the spanner) I removed the nut, cleaned the rust off, nut, and ring terminal, Refitted it and tightened it up, and when retested got 14.5 Volts.

So check your nuts !!

Radiotwo

Hi Again Toby

Actually that was a hint to add to your profile, so if any one has the test gear etc they know where you are !

Any way back to the charging etc, and this was not the same symptoms as yours, but my son-in-law has just had a problem with his 1.9TDi and I did a check on it, and when checking the voltage output (just over tickover 2000rpm) we were getting 13.2 Volts, and no more, I happened to touch the nut on the main connection on the alternator and it was hot, I got a spanner and found it loose(it was finger tight, but very loose with the spanner) I removed the nut, cleaned the rust off, nut, and ring terminal, Refitted it and tightened it up, and when retested got 14.5 Volts.

So check your nuts !!

Radiotwo

Check as well the connection of the alternator cable at the fuses by the battery. Common problem to have a poor connection there which can result in overheating of the connection/cable and melting of the plastic parts.

hi all,

i checked the operation of the alternator with a multimeter. the battery read 12v steady which went down a bit with the engine running to about 11.5v. revving the car up to around 2000rpm made no difference.

i tried the same test on a golf 3 and the voltage went up from about 13v to 14.3v with the engine running.

i'll check the wiring at the battery end tomorrow evening but a brief look earlier it looked ok, the fuses are intact and nothing looks melted.

i'll give the nuts a clean up - they look to have been covered in grease at some point but no idea when.

cheers for all info and help.

regards

toby

hi all,

i checked the operation of the alternator with a multimeter. the battery read 12v steady which went down a bit with the engine running to about 11.5v. revving the car up to around 2000rpm made no difference.

i tried the same test on a golf 3 and the voltage went up from about 13v to 14.3v with the engine running.

i'll check the wiring at the battery end tomorrow evening but a brief look earlier it looked ok, the fuses are intact and nothing looks melted.

i'll give the nuts a clean up - they look to have been covered in grease at some point but no idea when.

cheers for all info and help.

regards

toby

Hi Again

That voltage is far too low, at 2000rpm you should get 14.3 min voltage, so check your connections, but suspect the alternator which is at fault.

The cheapest repair is to change the Voltage regulator, remove the engine cover and have a look at the code numbers on the voltage reg on

the back end of alternator, its the black bit just above the main connection for the power lead, (but not the skoda part number) and do a Google

search and see if you can get a new reg, should be about £10/20

Radiotwo

evening,

i thought that as the voltage only went down from 12v that the alternator wasn't doing anything and the reduction was the car using some power for the igniton.

i'll still try the nuts and check for melted wires but i think the alternator is definately the prime suspect here.

as its dark and i have given the keys away to have a spare cut (no access to alternator until tuesday night) i can't play with the reg - is it a simple remove-replace job? i'll have a scout about and see if i can get the part number from an ebay picture....

thanks again Radiotwo - most helpful.

cheers

Edited 3 January, 201016 yr by toby

Halfords do a free battery check, that i believe checks the battery and alternator output.

It certainly shows pretty much exactly the same verdict as the battery checks from the RAC, so i'd be fairly confident they do a reasonable job.

i bought a new alternator from GSF for £100 in the end. fitting it is easy (did in yesterday afternoon in about an hour in the snow). it got dark then so i couldn't do the belt fully - i've got it around everything except the alternator. from doing this on other cars i hate the job although the tensioner is a nice arrangement compared with cars with alternators as tensioner. i'll go out in a bit a finish the job and re-connect the battery and hope all is well.

i think after checking the voltage from the battery with the alternator up to speed and getting the < 12v that at least something wasn't working in there. i'd have gotten it checked more thoughly but with the snow and things i didn't want to risk getting stuck and flattening the battery. at least now i should have piece of mind until it goes wrong again.

i'll update when i've got it going again.

thanks again for all your help.

cheers

toby

fixed - battery now showing 14.45v at tickover (checked after the recommended 10 minute adjustment time).

what i did for 1.6 AEH engine

remove lower/front ngine cover (3x10mm)

remove battery negative lead (10mm)

remove multi plug and unbolted (13mm) top wire and brown wire (earth?).

15mm open spanner on tensioner and pulled back - held with allen key through hole at the alternator side.

alternator belt off - in retrospect would have been even easier after removal of alternator.....

remove right hand nut (13mm) on top alternator mount hole - removal of complete brown earth wire.

un bolt top alternator bolt (13mm) - tensioner released halfway through for access.

un bolt bottom alternator bolt (13mm)

lever alternator out with suitable lever but held carefully.

remove bottom alternator cable (8mm bolt - two rings)

belt fitted at this stage (even with air-con on the 1.6 engine this isn't too hard - i've heard on TDI engines its a pain) but left loose

alternator fitted in reverse order as above but without the lower bolt and the top bolt left slightly loose

belt fitted over alternator pully then lower bolt fitted whilst lifting the alternator. then both bolts fully tightened.

tensioner released making sure the fitment is square over all 4 pulleys.

battery re-connected

engine started and left to idle for 10 minutes. i checked the voltage intitally and it read 14.8v this settled to 14.45 when i checked about 15 minutes later.

both belt and alternator (90A) from GSF @ approx £140 inc VAT time taken about 2 hours (in the snow - would have been quicker if i didn't have to keep slowly walking to the house for tools). there is was a £100 surcharge on the alternator i'll recoup when i dig the car out of the snow.

hope this helps if anyone has to do the same.

thanks again for help adn advice,

regards

toby