Is The Alternator On Its Way Out?

[humanz 3]

I've noticed in last few weeks since fitting a lightened crank pulley that when I switch my lights on, the battery light lights up faintly. It becomes more pronounced if I turn on the indicators or activate the brake lights. Also, if the lights are on, the car doesn't always want to start from cold. Have no problems starting the car with the lights off.

 

Is this a sign that my alternator is not charging the battery like it should? Could this be due to the lightened crank pulley I recently fitted?

Or is this a sign of some thing else?

 

The battery doesn't seem likely, as it has only recently been fitted, and it's a high quality one (read: expensive).

 

Car's currently at bodywork guy getting some repairs done.

[jackherer 543]

It could be a bad connection to the alternator, mine did it for ages then finally the main cable to the alternator snapped off at the ring connector, when I fitted a new connector the faint battery light never happened again.

[munster 0]

Sounds like the alternator to me.

If you find the battery light begins to stay on whilst driving, then most likely your alternator has gone.

I had this happen a few months back.

[humanz 3]

It could be a bad connection to the alternator, mine did it for ages then finally the main cable to the alternator snapped off at the ring connector, when I fitted a new connector the faint battery light never happened again.

 

How many connections are there on the alternator, and which one is the main cable? Will have a check early this week once I get the car back. Will check this before I start the search for an alternator.

[Nick_205GTI 0]

I have the same with my 205....although it seems to kick out a nice healthy 13v...., i have checked all the connections on mine and they are fine so its probably the brushes.

 

As for the number of connections there are 2.....but for lords sake if you are fiddling about with them dosconnect the earth off the battery as if you use a spanner and touch anything metal you will have fireworks!!

[DrSarty 90 1 Cars]

The lightened pulley has no effect on the function of the alternator.

 

Alternators should be kicking out about 14.4v (so that 13v mentioned above is concerning) and they only have two wired connections: charging output (the thick one that usually goes via the solenoid back to the battery positive) and the thin 'sensing' wire that goes to the dash light.

 

A dimly glowing light will be down (as said) to an alternator on its way out, a poorly thick cable either side of the solenoid or a weak earth somewhere, which you can usually track by observing it as you turn components on and off.

 

This test is best done at night to see the real difference. If it brightens with every component in turn, then I'd definitely say it's the alternator or associated thick wiring that's at fault.

[jackherer 543]

How many connections are there on the alternator, and which one is the main cable? Will have a check early this week once I get the car back. Will check this before I start the search for an alternator.

 

There are two connections to the alternator, a thin wire with a spade connector and a thicker wire with a ring connector. Cut the ring connector off the larger wire and crimp a nice new one one, then refit it making sure there is a toothed (also called star apparently) washer fitted. And as has been mentioned disconnect the battery before working on any of this...

[humanz 3]

My alternator has three wires. A thick one and a thin one with ring connectors attached on a post, and a thin wire connected near the bottom of the alternator. Will post pictures of the setup later. According to my analog multimeter, the battery is in good condition, and the charge from the alternator is around 14V. So both seem to be fine. I've cleaned up all the grounding points I could find except one by the fuel tank. I've noticed the light only comes on now when the headlights are on AND the indicators/hazard warning lights are activated.

 

Will try replacing the ring connector on the main cable this weekend and report back.

[hcmini1989 16]

My alternator has three wires. A thick one and a thin one with ring connectors attached on a post, and a thin wire connected near the bottom of the alternator. Will post pictures of the setup later. According to my analog multimeter, the battery is in good condition, and the charge from the alternator is around 14V. So both seem to be fine. I've cleaned up all the grounding points I could find except one by the fuel tank. I've noticed the light only comes on now when the headlights are on AND the indicators/hazard warning lights are activated.

 

Will try replacing the ring connector on the main cable this weekend and report back.

 

do you have access to an ammeter if so test it with that.just because its reading 14v doesn`nt mean its any good.get hold of an ammeter and see what it reads

have a look at this should be of use to you

 

http://www.prestolite.com/pgs_training/training_3.php

Edited December 21, 2009 by hcmini1989

[humanz 3]

Would a poorly operating alternator affect how much power is available for the ignition system?

[welshpug 1,666]

very much so yes

[dee205 3]

Sorry for hijack but instead of starting a new thread. What's the best alternator/battery setup to use on a 1.9 Mi16? Currently using a 50A alternator but I know some other models use a 70A. Also what rating of a battery to suit? Seen them from 55Aph up. I'm assuming they would need to match each other so as the correct charge is fed back into the system?

[DrSarty 90 1 Cars]

You don't need big batteries or alternators; you just need a system which is running healthily and meets the current demands of your car.

 

The more accessories you have (or have on regularly to be more accurate) the higher the current demand from the electrical system.

 

If you drive a lot with your lights on, the fan on, the heated rear screen on and 2 x 12" subs pounding away, then even a standard system will keep up.....UNLESS you only drive short journies, when the alternator won't have time to replenish the battery, and eventually you'll kill one, the other or both.

 

If you leave the car for long periods, then a battery will naturally drain. The larger the battery the longer it will last.

 

So it's horses for courses. There's no secret brand or recipe. You just need to match your components to the lifestyle your car endures and keep it running properly, i.e. clean the earths, upgrade the leads every 10 or 15 years I suppose, check the condition of the battery and keep the alternator belt at the correct tension and in good nick etc.

 

Naturally components fail, but usually something causes it.

[humanz 3]

I'd like to check the alternator as outlined in that link. But as mentioned before I have three wires to my alternator. One is the thick positive cable, so I assume the the cable attached to the same location will also be positive. Which means the thin cable near the bottom of the alternator (if looking down into the engine bay) is the negative wire? The photos are on my other system. Will try to upload them later.

[DrSarty 90 1 Cars]

Which means the thin cable near the bottom of the alternator (if looking down into the engine bay) is the negative wire?

 

No. Alternators like starter motors/solenoids usually always earth through their casing.

 

The thin wire will almost certainly be the sensing wire that goes to the light on the dash. If you ground it, the light should come on.

[Chris_Mi 6]

No. Alternators like starter motors/solenoids usually always earth through their casing.

 

The thin wire will almost certainly be the sensing wire that goes to the light on the dash. If you ground it, the light should come on.

 

I'll second that - just fitted a reconned alternator today. It had three terminals, a +ive (protruding bolt for a ring and nut connection), a -ive (same) and a spade connection for the excitor wire. My old alternator only had 2 wires connected - positive ring (thick wire) and spade (excitor). I didn't bother connecting the -ive with the new alternator. As Sarty says, it earths through itself, so this is not needed.

Works a treat - brighter lights, faster wipers, no battery warning light.

[jackherer 543]

I'd like to check the alternator as outlined in that link. But as mentioned before I have three wires to my alternator. One is the thick positive cable, so I assume the the cable attached to the same location will also be positive. Which means the thin cable near the bottom of the alternator (if looking down into the engine bay) is the negative wire? The photos are on my other system. Will try to upload them later.

 

We definitely need to see photos as three wires is not normal.

 

It sounds like the 'extra' wire is the one attached to the same terminal as the thick cable, someone has probably tapped into it for a 12v feed for something...?

 

The separate thin cable will be the excitor/battery light wire.

[welshpug 1,666]

3 wires is not normal for an 8v 205 alternator.

 

But it is on a 306 as they take the feed for the double relay directly from the alternator though IIRC both positives are on the same m8 stud and the exciter on another m6 stud with a much thicker wire than a 205.

 

Don't know the intricacies of BX wiring though.

[humanz 3]

It sounds like the 'extra' wire is the one attached to the same terminal as the thick cable, someone has probably tapped into it for a 12v feed for something...?

 

Merry Christmas all!

As Jackherer says, the extra wire is probably just a tap into a 12v feed.

[DrSarty 90 1 Cars]

Riiiight!

 

When you said 3 wires, it may have helped if you'd said how many terminals, which in this case seems to be 2 just like all of the alternators we've been talking about here.

 

EDIT: I've just looked back at your description, and that's where both sides got confused. There is a positive charging post and a dash light wire. That's what it should have.

Edited December 25, 2009 by DrSarty

[Guest rico260z]

Woops! 1st attempt to post on this site there as I'm a 205GTIDrivers newbie

 

Was just going to add that before you shell out for a new alternator check the brush/regulator unit (held on by 2 bolts and a spade connector) as I've just had the same problem with my 205 Gti alterntor and sticking on a new one of these did the trick and cost £12.75 rather than £70 + for an alternator.

 

The last 2 alts that have "gone" on my other cars were also fixed by installing new brush packs

[peakrevs 0]

My alternator has three wires. A thick one and a thin one with ring connectors attached on a post, and a thin wire connected near the bottom of the alternator. Will post pictures of the setup later. According to my analog multimeter, the battery is in good condition, and the charge from the alternator is around 14V. So both seem to be fine. I've cleaned up all the grounding points I could find except one by the fuel tank. I've noticed the light only comes on now when the headlights are on AND the indicators/hazard warning lights are activated.

 

Will try replacing the ring connector on the main cable this weekend and report back.

 

Not sure if this helps but the smaller eyelet connector goes to earth so perhaps worth checking that it does with a meter.

 

John

[humanz 3]

Well, a friend was having a similar problem. He had told me not to worry about it too much. Well, his belt popped the other night. He replaced the belt, and guess what, no more glowing battery light. So I've gotten a replacement belt and once I have a chance tomorrow, will replace the belt and see if the problem goes away. If it doesn't, I'll have to investigate the regulator unit and see if I can get a replacement here. Many motor factor places are on their Christmas holidays until after the new year, and 205 parts are getting really hard to come by. I'm almost certain the local ex-peugeot dealership has no more 205 parts in stock.

[davey205 7 1 Cars]

don't mean to hijack thread but i have slightly flickery lights could my alternator be shagged

[Guest rico260z]

The regulator/brush pack isn't a 205 part as such. It's a spare for the particular make and model of your alternator.

for instance mine was a Paris-Rhone spare for a Lucas LRA764 alt. So shouldn't be difficult to get.