At the suggestion of makefish...

Help!

CAR: Felicia GLXiE 1.3 N(95) Reg, Non-PAS

Cant afford new alternator atm.

Few Queries, I changed the belt about 6 months before this problem started occuring when it started squealing. Took old belt off and found to be disintegrating. Replaced it. First 2 months belt still made squealing noises, but about a week before i was goign to investigate, it stopped.

As i said abotu 6 months later my lights have been dimming to dangerously low levels when goign above 3200rpm in any gear. At the same time my car is also finding it hard to start, this week, ive had to jump it 4 times!

Tested battery and comes up as "good but recharge", Recharge it and fine for about a week-fortnight, then start up problems begin. I do do a lot of short (less than 5 mile journeys) which im aware can cause electrical problems, but make a 60 mile round trip at least once a month

Have been told the belt may have loosened, which is causing current problems, so need to check that. How will i tell if its too loose tho?

Also if it isnt too loose, been told next step is to check the wiring leading to it for corrosion, but i cant see it being that as it appears to be a speed/revolution related problem.

Is the next step to check the alternator brushes? I repair washing machines outside of college, so im used to changing wm brushes, can you do the same with felicia alternators? assuming brushes are available?

Any help would be much appreciated as im quite poor atm! (just had rear shocks replaced)

Assuming you don't have any extraordinary power hungry ICE equipment - this info may help for checking the alternator/ regulator -

@4000rpm - Output should be 14V / 37A [AutoData 2004]

(May not be too easy to check the current)

As you've suggested, I would say that it's definitely worth checking the brushes, cleaning, etc. Not sure..but I think that the regulator/ brush unit can be removed by a couple of screws from the back of the alternator (behind the plastic cover).

If the regulator is at fault, I think it's the case that the output voltage will vary and may be too high. A replacement regulator is a relatively cheap unit to replace. JHB list this at about £15 - may be cheaper from dealer.

If the complete alternator does need replacing, could you get a second hand unit from salvage/ breakers yard?

cheers for that. do you know of any tutorials on the web as to how u go about doing this? or do u have any tips on what i need to be doing ?

Also never taken a voltage reading on an alternator before, what do i need to use (got a yellow multimeter thing somewhere) what settings i need to set it to, and have you got any pics as to where i put my contacts on the alt.

second hand parts are possible i guess but id rather be happier in the knowledge that a new one was in there, rather than one that could go wrong at any time.

Set the multimeter to the D.C. Voltage scale (<20V)

Put leads across battery terminals......

engine not running......should read about 12V

engine running............should read up to 14V

These readings will drop when you switch on any electrical equipment.

See what the voltage readings are when you increase engine speed...i.e. up to and past the 3200rpm you mentioned (probably need someone else on the pedal).

From my understanding...if the voltage readings look to be erratic and rise well above the 14V, then it is likely to be a regulator fault.

Unfortunately not so easy to measure the current, as far as I am aware, as you need a meter 'in line' on the alternator supply cable, and also a meter that is capable of measuring the size of current. I think you can get 'clamp meters' that just hook over the cable to measure the current - but these will obviously be expensive. May have to hand this over to an auto electrician for this one.

Are you a member of AA/ RAC, etc...You could callout them to diagnose the fault.

This is about as much as I know I'm afraid. Perhaps an auto electrician would be able to test it for a few quid. A 'Google' may help or the Haynes has a bit of information.

At the suggestion of makefish...

Also if it isnt too loose, been told next step is to check the wiring leading to it for corrosion, but i cant see it being that as it appears to be a speed/revolution related problem.

Definitely worth checking for any obvious loose/ corroded wiring. If there is no charge being pumped into the battery due to poor wiring - as the engine speed increases, more current will be drawn for the spark and hence the lights will dim.

Just another thought.....

Does the battery light illuminate on the instrument panel before you start the car?

Depending on the type of charging circuit....I have had previous cars where simply a blown 'ignition warning light' bulb breaks the charging circuit and therefore the alternator doesn't charge the battery.

as the engine speed increases, more current will be drawn for the spark and hence the lights will dim.

it actually requires less current at higher rpm to create a spark than at a lower rpm because the mixture in the combustion is hotter......

i think the problem is more likely to be the alternator voltage regulator

it actually requires less current at higher rpm to create a spark than at a lower rpm because the mixture in the combustion is hotter......

OK, wrong again!......

But surely there must be more power being drawn from the ignition circuit. The spark is having to be generated so many more times per second?

OK, wrong again!......

But surely there must be more power being drawn from the ignition circuit. The spark is having to be generated so many more times per second?

the energy used by the ignition coil is allways the same, because of the huge internal capacator, it's just that less of it gets wasted as heat at higher rpm's

Thanks for the correction...useful information.