Lucas Regulator and/or Relay Problem

[Graham Pearson]

Appreciate any help with this problem.

Alternator is an aged but working Lucas CAV AC5 24V (puts out 35 amps) which has been removed and bench tested to confirm working & charging.
External regulator is equally aged Lucas type 572-10 sealed unit.
There is a relay (if this is the correct name for it) that I believe is in the closed position when the ignition is on (with alternator warning lamp lit) and then opens when engine starts (alternator warning lamp goes out).
There is a problem but I don't know if it is the regulator or relay or both.
Workshop manual is very clear and states:

"Warning lamp does not light up when switched on"...disconnect "F" lead at regulator and connect it to the negative terminal. Switch on. If warning lamp lights up, the regulator is faulty. If lamp fails to light up, the alternator is faulty".
Have done as instructed and lamp does not light (but I know the alternator is ok). However, when I manually close the relay with my finger, the lamp lights.

I imagine that the manual instructions don't take into account the possibility of a potentially faulty relay. Also, I don't know if the relay works independently of the regulator and the relay is faulty or if the relay receives current via the regulator, is not receiving any and consequently the regulator is faulty.

Have nice clear pics of regulator and relay (if someone would be kind enough to explain how to upload them, from a Mac) if this might help to solve problem.

Thanks for reading
Graham

 

[VicS]

Appreciate any help with this problem.

Alternator is an aged but working Lucas CAV AC5 24V (puts out 35 amps) which has been removed and bench tested to confirm working & charging.
External regulator is equally aged Lucas type 572-10 sealed unit.
There is a relay (if this is the correct name for it) that I believe is in the closed position when the ignition is on (with alternator warning lamp lit) and then opens when engine starts (alternator warning lamp goes out).
There is a problem but I don't know if it is the regulator or relay or both.
Workshop manual is very clear and states:

"Warning lamp does not light up when switched on"...disconnect "F" lead at regulator and connect it to the negative terminal. Switch on. If warning lamp lights up, the regulator is faulty. If lamp fails to light up, the alternator is faulty".
Have done as instructed and lamp does not light (but I know the alternator is ok). However, when I manually close the relay with my finger, the lamp lights.

I imagine that the manual instructions don't take into account the possibility of a potentially faulty relay. Also, I don't know if the relay works independently of the regulator and the relay is faulty or if the relay receives current via the regulator, is not receiving any and consequently the regulator is faulty.

Have nice clear pics of regulator and relay (if someone would be kind enough to explain how to upload them, from a Mac) if this might help to solve problem.

Thanks for reading
Graham

Completely puzzled by this relay. Not normally a relay involved with an alternator waning light. Got an alternator with an external regulator .. no relay... warning light connected directly to the alternator.

Got a wiring diagram of alternator with an electro-mechanical regulator .. no relay there either.


Can you not upload pictures, as attachments, from a Mac as you would from a PC
Personally always use Photobucket anyway.

A wiring diagram would be more useful than a picture


Check the relay coil for continuity .... even test it on a battery to see if it operates.

Halcyon will be along in minute to explain why there is a relay!

How do you manually close it if its sealed?

 

[halcyon]

Appreciate any help with this problem.

Alternator is an aged but working Lucas CAV AC5 24V (puts out 35 amps) which has been removed and bench tested to confirm working & charging.
External regulator is equally aged Lucas type 572-10 sealed unit.
There is a relay (if this is the correct name for it) that I believe is in the closed position when the ignition is on (with alternator warning lamp lit) and then opens when engine starts (alternator warning lamp goes out).

Were going back, it is a relay that controls the warning light.

I've got some old Lucas / CAV alternator training manuals in the workshop, if you don't get an answer I'll have a look in the morning.

Brian

 

[Graham Pearson]

Thanks for replies...Sorry Vic S. don't have wiring diagram ...trying to at least upload photos but no joy so far. Have created file for pics but don't know how to upload.

 

[VicS]

Were going back, it is a relay that controls the warning light.

I've got some old Lucas / CAV alternator training manuals in the workshop, if you don't get an answer I'll have a look in the morning.

Brian

relay coil in the circuit where normally there'd be warning light.... light operated by the relay? As simple as that?

 

[VicS]

Thanks for replies...Sorry Vic S. don't have wiring diagram ...trying to at least upload photos but no joy so far. Have created file for pics but don't know how to upload.

Created file for pics ??? Not trying to upload the to an album on here are you ... no good have to get them moderated before you can use them.

Click "Go advanced" then" Manage attachments" , "add files", Select files, browse to the pics you want and select ( double click on a PC) then upload files. Bu**er failed ....size limit applies )


I always use Photobucket !

 

[halcyon]

relay coil in the circuit where normally there'd be warning light.... light operated by the relay? As simple as that?

Don't think it that simple, regulator controls coil, contacts control the warning light, it goes back to the 1970's, used to run a alternator exchange outfit then, hence hazy memory.

Brian

 

[VicS]

Don't think it that simple, regulator controls coil, contacts control the warning light, it goes back to the 1970's, used to run a alternator exchange outfit then, hence hazy memory.

Brian

Would it be appropriate to test the relay by connecting the coil to the battery as I suggested earlier or is the coil likely to be a lower voltage rating.

 

[Graham Pearson]

Finally got my pics..thanks for help Vic S. Installation dates from late 70's...starting to think I might have to junk the whole thing. Any positive comments welcome!

 

[VicS]

Finally got my pics..thanks for help Vic S. Installation dates from late 70's...starting to think I might have to junk the whole thing. Any positive comments welcome!

I wonder if that an old electro-mechanical regulator. They worked like the regulator in old dynamo control boxes.

It would be interesting to find out whats wrong.. it may only need a new relay. I'd at least check the coil for continuity

A good automobile electrician should be able to sort out a modern regulator that would work without needing the relay, if that's the route you want to take.

 

[Graham Pearson]

Here' another one..first time I've done this!

 

[halcyon]

Finally got my pics..thanks for help Vic S. Installation dates from late 70's...starting to think I might have to junk the whole thing. Any positive comments welcome!

It is probable that they have replaced the old mechanical reg with the new electronic one with the blue label, pic 2, the relay may be from the original system.

You should be able to connect the warning light to the WL terminal on the new regulator, and all should work.

Brian

 

[nigelmercier]

Installation dates from late 70's...starting to think I might have to junk the whole thing. Any positive comments welcome!

What about negative ones?

Honestly? Get a new smart regulator, your batteries will love you for it.

 

[Graham Pearson]

Thanks Brian, assume by electronic one with blue label you mean the one marked "Lucas"....the WL terminal on the regulator already has a wire attached, so what would I do with it?
apologies for my obtuseness

ok Nigel, negative comments welcome too, if I were to instal new regulator what should I be looking at and would I have to change ancient (but working) alternator?

thanks for all contributions
Graham

 

[halcyon]

Thanks Brian, assume by electronic one with blue label you mean the one marked "Lucas"....the WL terminal on the regulator already has a wire attached, so what would I do with it?
apologies for my obtuseness

From your earlier post the relay is connected, it's a matter of finding were the wires go. It's possible that the new regulator has been piggybacked onto the old mechanical unit. The WL wire may be going to the relay coil, you need to follow the wires and find what goes were.

It's possible they have damaged the regulator if they have the relay coil connected, higher load than a bulb, that's why it's stopped working.

But first sort out a wiring diagram.

Brian

 

[nigelmercier]

if I were to instal new regulator what should I be looking at and would I have to change ancient (but working) alternator?

I've got a Balmar Max Charge, it is awesome: http://www.balmar.net/PDF/regulator info s/MC-614.pdf
Expensive though, but there are others, for example: http://www.sp-shop.co.uk/Sterling-Power-Digital-Advanced-12v-Alternator-Regulator-AR12VD.html

No need to change the alternator, although a modification may be needed if it has a built-in regulator.

 

[pampas]

You have the Full works, supressed system excellent when working.

Trace out where the w/l connection goes. as said you can put the warning light straight to the lucas regulator but I think you may find that the contactor is connected via the oil pressure switch to enable the engine to run up to speed before the alt. loads the engine.

Another point it to get the lucas regulator tested since it is a very old model and it may have devloped a fault internally. Even though it looks in good condition, as said in other posts take any bits to a good auto/lecky repair shop.
First thing to do is trace the coil connections,2, test coil on 12v supply(Assuming its 12V not 24) to see if it works ok( Put a bit of thin paper between points for safety when testing) and take it from there.

a long time since working on one of these systems and the grey matter now fading a bit. Best of luck
Gordon

 

[Sandyman]

I have the same 24v regulator & alternator but no relay. My problem is that the ign light stays on even when ignition is off. Have yet to investigate.
Need to replace painters hat with electricians hat before hand

OP. The regulator is still commonly available. I bought two as spares year before last. Around 17 quid as I recall on Ebay.
You can also still get all spares for the alternator. Again on Ebay from a motor factors in N London.
Any prob with spares get back to me & I will look out the Company name & address 4U.

 

[TQA]

WOW I am surprised to see one of these still working in a marine environment. Did you take the cover off for the photo?

I am pretty sure the relay is used instead of the extra 3 diodes that a modern alternator has and is concerned with the warning light.

I think you need both the relay and the regulator.

If there is any expense involved I would junk it and get a modern alternator with an integral regulator. If you use your main engine to recharge batteries in a big way as others have said a modern 'smart' external regulator is a good investment.

 

[Graham Pearson]

Thanks to all for the interest & help;

Yes TQA took cover off for the photo & guess where the wiring diagram was?, stuck to the cover on what looks like a bit of parchment!

Might be interested in spares pampas but unless they are identical, doubt I will be clever enough to fit them (I'm already pretty much in over my head).

Hope all will be clear from diagram...should point out that with assistance from a chum who is brighter than me, we have been completely unable to locate the "type 448 fuse" mentioned between battery & ammeter and doubt that it was fitted.

The relay I was on about seems to be referred to as part of the "surge protection unit" but I thought all the clever electronics in the regulator was supposed to take care of that?

Most grateful for any additional thoughts especially how I test for continuity in the relay/coil.

Graham