60ah + Alternators?

[BaileyMex]

Morning all, 

So I'm not sure if my Alternator is on its way out or another issue, when driving at night and stationary with the engine running and lights on, they are dim and flicker, but when you rev the car they get brighter and the flickering stops. No other stereo or anything running.

Could this be a sign the alternator is not putting out enough power to charge the 60ah battery I have in the boot?

I have a really old - 20+ year old Lucas ACR type style standard alternator, not sure what the output ah rate is as there are no markings, the sticker has long perished. What ah would have been standard?

I'm sure basic maths will answer the next question, but if I fitted a 80ah alternator would that fook the battery and cause problems?

Thoughts people?

Cheers

 

 

[Nige65]

Mine started to do exactly what you have described, I replaced it with one of these:

PCA00100LUC Genuine Lucas Classic Alternator Remanufactured 18 ACR - (gsparkplug.com)

 

Edited September 15, 2023 by Nige65
Grammer/spelling

[katana]

1st Q - what about the ignition / charging warning light - what is that doing as that is its primary function?

Yes the alt. could be failing but before spending coin, put a multimeter set on DC volts across the battery with engine off, idling and higher rpm. Results should be approx. 12.5v, 13.8-14.0v and 14.5-14.6v respectively. If your results are not similar then it does point to a failing Alt.

But your battery is the sump for the alt output and its purpose is to level out system voltage so dimming lamps shouldn't generally occur - minor dimming like dash lights dimming when using indicators say, is symtomatic of boarderline alt. output being low for system requirements ie. in winter where everything is switched on and drawing on the battery. So i'd get your battery load checked as well as that may be the primary problem !

Oh and personally I wouldn't go bigger alternator than the battery capacity unless you have a LOT of always on electricals that can use the output - like modern cars. Ford sized the alt. to just about cope with most situations but with a dip in the most extreme so upping from, say, a 35A upto a 45A would be sensible into a 60A battery but IMO an 80A alt into a 60A battery wouldn't

Edited September 15, 2023 by katana

[BaileyMex]

1 hour ago, Nige65 said:

Mine started to do exactly what you have described, I replaced it with one of these:

PCA00100LUC Genuine Lucas Classic Alternator Remanufactured 18 ACR - (gsparkplug.com)

 

Cheers mate, I take it the new alternator cured it? I can see from the web link that it states it's 34amp are amps the same as Ah (amp hours)?

https://www.gsparkplug.com/pca00100luc-lucas-remanufactured-18-acr-powerlite-classic-alternator-lucas-pca.html

My battery is 60ah, and Burtons offer a 60A alternator, would logic suggest that would be more suitable for me? https://www.burtonpower.com/lucas-acr-style-60a-alternator-rh-mounting-acr60rh.html

[BaileyMex]

10 minutes ago, katana said:

1st Q - what about the ignition / charging warning light - what is that doing as that is its primary function?

Yes the alt. could be failing but before spending coin, put a multimeter set on DC volts across the battery with engine off, idling and higher rpm. Results should be approx. 12.5v, 13.8-14.0v and 14.5-14.6v respectively. If your results are not similar then it does point to a failing Alt.

But your battery is the sump for the alt output and its purpose is to level out system voltage so dimming lamps shouldn't generally occur - minor dimming like dash lights dimming when using indicators say, is symtomatic of boarderline alt. output being low for system requirements ie. in winter where everything is switched on and drawing on the battery. So i'd get your battery load checked as well as that may be the primary problem !

Cheers Katana,

Red ignition light stays on for a bit when you first start the car after it has been standing for a week or two, but after a few revs or a few mins if idling it will go out.

I'll check the DC volts later, will need a helping foot to rev the car whilst in the boot hahaha

 

 

[Rally Pack 2000]

56 minutes ago, BaileyMex said:

Cheers Katana,

Red ignition light stays on for a bit when you first start the car after it has been standing for a week or two, but after a few revs or a few mins if idling it will go out.

I'll check the DC volts later, will need a helping foot to rev the car whilst in the boot hahaha

 

 

I had an alternator thread going recently. For 5 to 10 quid you can check constantly if you have a cigarette lighter socket. Well worth the money.

If your alternator is an original early one its 35amp but if its re-manufactured later one it will be 45amp. The way you describe the light going out after a few revs  was always common place with cars with batteries in the boot. There is a bit of a loss there through the cabling. I think a 60amp one would probably be helpful in your situation. I do have issues with the quality of these Chinese replicas though. Both mine were faulty however the replacement just needed its rectifier realigned so you could plug it in but short of switching to Bosch the Chinese ones are all that's on offer. I do think it would solve your problem though. Before you go spending the cash though double check all your earth and terminal leads are clean and fresh.

[BaileyMex]

Cheers mate, will do and thanks 

Multi meter is in the other car which the Mrs has at work at the moment, so will have to wait until later to check voltage

[Miniliteman]

The symptoms you describe it can be either a alternator that cannot supply enough Amps or has a (or more) defective rectifier diodes, or a battery that is old and cannot keep the full charge (modern batteries) or the wiring from alternator to battery to fuses is old or too small or what I see a lot is the connections of the wiring are not good.

Battery size is measured in Ah, Amp x hour. A 60 Ah battery can (theoretically) provide a 1 Amp current for 60 hours. Alternators specs are given by Voltage and Amps. A 35 Amp alternator can supply (when all is ok) a 35 Amp current at a specified rpm (normally 4000 or so).

[BaileyMex]

Thanks mate, the battery is quite old, but it holds its charge fine and always starts ok, will do as Katana suggested later with the multi metre and check that for starters.

As said, the Alternator is proper old so it could just be that, and the connections all seem to be sound, but will re-check.

Its not the end of the world, just an annoyance really, didn't get home in it last night until nearly 10pm, and very apparent with the dimming/flickering headlights.

👍

[BaileyMex]

On 15/09/2023 at 09:52, katana said:

Yes the alt. could be failing but before spending coin, put a multimeter set on DC volts across the battery with engine off, idling and higher rpm. Results should be approx. 12.5v, 13.8-14.0v and 14.5-14.6v respectively. If your results are not similar then it does point to a failing Alt.

OK, so managed to get the figures over the weekend.

Engine off = 12.58v

Idling from cold = 12.2 - 12.6

Under load = 14.02 - giving it moderate revs not redline haha

Running with lights on = 12.2

 

[katana]

Its goosed!

[BaileyMex]

10 minutes ago, katana said:

Its goosed!

Ha! Goosed!

Cheers mate, OK, I've ordered a 60a one from Burtons to hopefully feed the 60ah battery that seems to be ok.

[Miniliteman]

1 hour ago, BaileyMex said:

OK, so managed to get the figures over the weekend.

Engine off = 12.58v

Idling from cold = 12.2 - 12.6

Under load = 14.02 - giving it moderate revs not redline haha

Running with lights on = 12.2

 

Idling from cold: is the charging light on or off?

Running with lights on: is the charging light on or off or flickering and at what rpm did you try that?

[BaileyMex]

1 hour ago, Miniliteman said:

Idling from cold: is the charging light on or off?

Running with lights on: is the charging light on or off or flickering and at what rpm did you try that?

When idling from cold - The light stays on for a min or two until I've given it some revs and then it goes out once its woken up a bit 

[Rally Pack 2000]

2 hours ago, BaileyMex said:

When idling from cold - The light stays on for a min or two until I've given it some revs and then it goes out once its woken up a bit 

To be fair that sounds like standard Mk1 to me till they wake up a bit. If its on while driving or flickering at night when you turn the lights on then it may be time to replace the alternator.