Alternator recommendations

[Pug]

I'm pretty sure my alternator needs replacing. I've tested the output both at the battery and also at the two red wired terminals on the alternator itself. They measure 12.5 volts at tick over and there's no change when the engine is revved.

There's no markings on my existing alternator so I'd like to know what specification I need. Details are:

1979 Escort currently fitted with a 1600 xflow (now1700cc). 

70 Ah battery in the boot.

Current alternator has 3 terminals, two thick red wires and a thinner blue one (which I assume goes to the ignition light?)

Recommendations on make would be welcome too.

[Vista Estate]

53 minutes ago, Pug said:

I'm pretty sure my alternator needs replacing. I've tested the output both at the battery and also at the two red wired terminals on the alternator itself. They measure 12.5 volts at tick over and there's no change when the engine is revved.

There's no markings on my existing alternator so I'd like to know what specification I need. Details are:

1979 Escort currently fitted with a 1600 xflow (now1700cc). 

70 Ah battery in the boot.

Current alternator has 3 terminals, two thick red wires and a thinner blue one (which I assume goes to the ignition light?)

Recommendations on make would be welcome too.

I think you will have a lucas 18ACR fitted ( photos would help). 

It could be an AC Delco or Bosch too so without a photo it's not easy to confirm.

If its an original and stamped Lucas then I would get it repaired and uprated to 50amp output.

There are a few aftermarket ones available but they are a mixed bag.

Normal alternators pump out about 14 - 15amps when car is running. When loaded it should be at least 12.5amps.

The amp hour output of the battery is immaterial.

[Nige65]

I replaced my faulty alternator with this one:

 

[Pug]

44 minutes ago, Vista Estate said:

I think you will have a lucas 18ACR fitted ( photos would help). 

It could be an AC Delco or Bosch too so without a photo it's not easy to confirm.

If its an original and stamped Lucas then I would get it repaired and uprated to 50amp output.

There are a few aftermarket ones available but they are a mixed bag.

Normal alternators pump out about 14 - 15amps when car is running. When loaded it should be at least 12.5amps.

The amp hour output of the battery is immaterial.

I think you are right that it's a Lucas! 

[Pug]

So the view is that it's better to get a refurbished Lucas?

[Pug]

I 

2 minutes ago, Pug said:

I think you are right that it's a Lucas! 

I mean a Lucas substitute 

[Vista Estate]

39 minutes ago, Pug said:

I think you are right that it's a Lucas! 

Yes you definitely have a Lucas. @Nige65seems to have got a good one. Aftermarket ones are hit and miss @Rally Pack 2000 knows all about that.

Lucas as a company don't exist anymore.

If you have a local company who can refurbish and upgrade yours I would go with that first. If not get the one @Nige65 got. Greenshank Plug are a good outfit. Make sure it's a 50amp upgraded one. It only puts out what you need but it's then not working at max capacity. The old 18ACR was about 30amp.

Be careful when you plug in the back as you can move the connectors.

I assume you will fit a new fan belt too.

Finally, if you haven’t done this before you have to loosen the bolt behind the pulley that holds the slider. This bolt also fixes the water pump. So just loosen a small amount so the slider bar can move up and down. Undo too much and there is a chance you could get a leak. Don't forget to tighten it back up.

[Pug]

Thanks vista for the useful advice. 

I've now taken the alternator off and found that the the lower bracket is about 6mm shorter than the lug spacing on the alternator. There's some extra washers etc to make up for this. It also has two separate bolts rather than one long one going through both lugs. Is this normal?

[Vista Estate]

Yes it's normal to have two separate bolts on the lower bracket.

You generally had one bolt when it was a dynamo.

There should be a sleeve on one hole (usually the back one) that moves to make up the difference as this alternator fits many cars.

If you notice the back one will be bigger than the front one ( no laughter at that OSF members!) If the sleeve is missing. If yours has washers the sleeve is missing and it won't be aligned properly.

 

[Vista Estate]

If you haven't changed your fan belt before then use a piece of string to check length and measure width too. It's easy to get the wrong one @Pug as there are ones for pinto and with dynamo.

[Pug]

15 minutes ago, Vista Estate said:

Yes it's normal to have two separate bolts on the lower bracket.

You generally had one bolt when it was a dynamo.

There should be a sleeve on one hole (usually the back one) that moves to make up the difference as this alternator fits many cars.

If you notice the back one will be bigger than the front one ( no laughter at that OSF members!) If the sleeve is missing. If yours has washers the sleeve is missing and it won't be aligned properly.

 

Thanks for the information. If it was a dynamo the last time I done something like this it must have been a long time ago 😳

I do have a sleeve for the back but a very long bolt which is probably not standard. I'll sort some more appropriate bolts when I put it back.

[Pug]

17 minutes ago, Vista Estate said:

If you haven't changed your fan belt before then use a piece of string to check length and measure width too. It's easy to get the wrong one @Pug as there are ones for pinto and with dynamo.

Good tip, thanks.

[Vista Estate]

4 minutes ago, Pug said:

Thanks for the information. If it was a dynamo the last time I done something like this it must have been a long time ago 😳

I do have a sleeve for the back but a very long bolt which is probably not standard. I'll sort some more appropriate bolts when I put it back.

Make sure they are put in with copper slip or use stainless as they get crap chucked at them.

It's worth putting a bit on the slide as well.

It makes it easier to move and adjust.

Edited June 25, 2024 by Vista Estate
Added extra info

[Pug]

5 minutes ago, Vista Estate said:

Make sure they are put in with copper slip or use stainless as they get crap chucked at them.

It's worth putting a bit on the slide as well.

It makes it easier to move and adjust.

👍

[Miniliteman]

3 hours ago, Vista Estate said:

Normal alternators pump out about 14 - 15amps when car is running. When loaded it should be at least 12.5amps.

The amp hour output of the battery is immaterial.

amps should be volts.

Over here most of the alternators are Bosch. They last forever. After many miles (hours) the voltage regulator might need replacing as the integral brushes are worn. Check if you can replace the regulator with the brushes (or the brushes alone) on your Lucas.

[Vista Estate]

23 minutes ago, Miniliteman said:

amps should be volts.

Over here most of the alternators are Bosch. They last forever. After many miles (hours) the voltage regulator might need replacing as the integral brushes are worn. Check if you can replace the regulator with the brushes (or the brushes alone) on your Lucas.

Thanks @Miniliteman, I spotted the error but it was too late to edit.

I managed to get some regulators for @Rally Pack 2000but genuine ones are not easy to find now, plus if @Pugis not used to stripping the alternator then it could be a problem.

I would check the bearings and windings too as there is no way to know how old the alternator is.

[Pug]

1 hour ago, Miniliteman said:

amps should be volts.

Over here most of the alternators are Bosch. They last forever. After many miles (hours) the voltage regulator might need replacing as the integral brushes are worn. Check if you can replace the regulator with the brushes (or the brushes alone) on your Lucas.

 

[Pug]

Just now, Pug said:

 

 👍

[Vista Estate]

Morning @Pug if you haven't already bought an alternator from the Green Spark Plug Company there is a discount code on at the minute till Sunday.

[Pug]

5 hours ago, Vista Estate said:

Morning @Pug if you haven't already bought an alternator from the Green Spark Plug Company there is a discount code on at the minute till Sunday.

Thanks for this. In the end I got a repair kit which I fitted this morning and pleased to say that my alternator is working properly now.

Thanks again for everyone's advice!

[Vista Estate]

3 hours ago, Pug said:

Thanks for this. In the end I got a repair kit which I fitted this morning and pleased to say that my alternator is working properly now.

Thanks again for everyone's advice!

Great, were the shaft bearings OK?

Glad you could repair it.

[Pug]

30 minutes ago, Vista Estate said:

Great, were the shaft bearings OK?

Glad you could repair it.

Yes, bearings ok as were the brushes. The alternator didn't look that old so must have been a failed rectifier or regulator.

[Vista Estate]

21 minutes ago, Pug said:

Yes, bearings ok as were the brushes. The alternator didn't look that old so must have been a failed rectifier or regulator.

Great news. 👍

[Dave Knight]

Cracking thread. This is what it’s all about. Like minded people with a love for classic Fords helping each other out.

[Rally Pack 2000]

On 26/06/2024 at 01:44, Pug said:

So the view is that it's better to get a refurbished Lucas?

 

On 26/06/2024 at 02:31, Vista Estate said:

Yes you definitely have a Lucas. @Nige65seems to have got a good one. Aftermarket ones are hit and miss @Rally Pack 2000 knows all about that.

Lucas as a company don't exist anymore.

If you have a local company who can refurbish and upgrade yours I would go with that first. If not get the one @Nige65 got. Greenshank Plug are a good outfit. Make sure it's a 50amp upgraded one. It only puts out what you need but it's then not working at max capacity. The old 18ACR was about 30amp.

Be careful when you plug in the back as you can move the connectors.

I assume you will fit a new fan belt too.

Finally, if you haven’t done this before you have to loosen the bolt behind the pulley that holds the slider. This bolt also fixes the water pump. So just loosen a small amount so the slider bar can move up and down. Undo too much and there is a chance you could get a leak. Don't forget to tighten it back up.

 

On 26/06/2024 at 05:10, Vista Estate said:

Thanks @Miniliteman, I spotted the error but it was too late to edit.

I managed to get some regulators for @Rally Pack 2000but genuine ones are not easy to find now, plus if @Pugis not used to stripping the alternator then it could be a problem.

I would check the bearings and windings too as there is no way to know how old the alternator is.

Go with refurbished if you can! These Chinese replicas are just a lottery. I had three faulty in a row! One trouble with refurbishing is they do it using the same crappy Chinese regulators and rectifiers that cause the problems in the complete replica alternators. So you need to do a bit of parts shopping yourself and give it to the Auto Electricians that  are refurbishing the alternator for you. You dont have to be stuck on all original Lucas stuff either you can get quality aftermarket ones made in the UK like Intermotor. Just ask the sellers where they are made and its usually written on the packaging. Their stuff is always good. It doesn't help though if you want to do the swap quickly though so I always have a rebuilt spare now to do a swap while the other is being refurbished.