Thread: S2a generator to alternator ?

This is relatively easy - I first did it in 1966. The Lucas generators are notoriously unreliable in Australian conditions, mainly due to the bush at the brush end not being protected from dust - plus it often gets missed in servicing.

Unfortunately I haven't done it for about ten years so I can't give any useful recommendations on what is a good alternator currently - but any that will physically fit would be best - the output will not be critical. Ideally get the alternator brackets off a Series 3 rather than adapt the generator bracket like I did. The wiring will vary slightly, and if yours has an ammeter (originally positive earth) it is better not to run the alternator lead through it, which further changes the wiring.

There should be someone here who has done it recently and can be more specific, alternatively any auto electrician should be prepared to do it for you.
John

Hi
I feel compelled by the sorry lack of response to chuck in my 2 bob worth.

I changed a few vehicles over to alternators and at least one back to Generator for authenticitys sake.

Before I start I will agree that one of the main reasons the old generators die is the bearing that is not protected from dirt etc. There are new / reconditioned versions form the prince himself (Lucas) that have solved this problem. The generator setup when properly maintained does work quite well enough. The old control box will have to be removed or at least disconnected. Also remember the wiring was designed for lower currents so don't over do it.

The alternator option can be a good option as it is relatively maintenance free. The main cars i changed were old and English with Lucas generators. I opted for early lucas alternators rather than the latest modern versions. I went for a lucas 11ACR or 13ACR The R means it has the regulator built in. You could use almost any alternator as almost all have the regulator built in these days.

Check that the brushes and bearings are in good condition.

I would choose one that is easily fitted to your car. so if a later version had an alternator i would get one of those with the pulley and mount bracket. It is very important to have the mount so the pulley is dead in line with the other pulleys. It is also important to have the correct pulley on the alternator as they usually run faster than generators. This may mean the pulley on the crankshaft may be different. I would look at the later motor and compare with yours. Alternators usually work in both directions ie CW and CCW but the cooling fan needs to be the right one.

Basically the alternator will have 2 terminals on the back. The main large terminal is the output and connects to the battery with a big heavy duty high current wire. The smaller connector is usually a charge terminal. It has 2 functions One is to indicate that the alternator is charging. The other is to turn the alternator on and off. This terminal usually connects to the ignition (12v when motor running position) circuit via a charge lamp. The lucas 11ACR used a 2.2w 12v lamp in series. Ie wire from alternator to one side of lamp and other side of lamp connects to the ignition.
I would search for the specific type you find on the web for connection details.

Feel free to ask more questions and i will see what i can answer for you.

zwitter

thankyou very much Zwitter.
i had a good fiddle with the generator and did some tests and found out that it is ok! turns out that it is either wiring or the regulator. The regulator cutout is possibly cutting in to early. I used a piece of paper to block the cut out solenoid and i get voltage and the charge light goes out BUT still no charge registering over the battery terminals. I fiddled some more and now the charge light goes out with normal operation (paper removed) but still no battey charge. I think there must be some dodgy wiring going on. I also have a block below the regulator which the generator connects to and then to the regulator. All i can think of is that it is some form of early circuit breaker. More testing i think is required !

thanks for the help,

Peter

Another thing to consider is that most British generator equipped vehicles (dunno about later Land Rovers) were positive earth.

If you change to an alternator, it will almost certainly be negative earth. This will affect any radio you may have fitted - and your starter motor as well as any instrumentation.

It's easy to flash a positive earth system to negative earth (except radios and other electronioc items).

I've got an article about this on my home PC. I'll hunt it down and post it on my website when I get home from work.

Ron

Originally Posted by p38arover

Another thing to consider is that most British generator equipped vehicles (dunno about later Land Rovers) were positive earth.

If you change to an alternator, it will almost certainly be negative earth. This will affect any radio you may have fitted - and your starter motor as well as any instrumentation.

It's easy to flash a positive earth system to negative earth (except radios and other electronioc items).

I've got an article about this on my home PC. I'll hunt it down and post it on my website when I get home from work.

Ron

I drove/tried to maintain many a british car before I left some 15 years ago, and the only vehicles that I came accross that were pos earth were the early mini's and morris 1100 (and their derivatives riley, wolsey etc.,) but that was only for 2 - 3 years - when BLMC discovered that poss earth causes advanced bodywork corrosion.

Originally Posted by p38arover

Another thing to consider is that most British generator equipped vehicles (dunno about later Land Rovers) were positive earth.

If you change to an alternator, it will almost certainly be negative earth. This will affect any radio you may have fitted - and your starter motor as well as any instrumentation.

It's easy to flash a positive earth system to negative earth (except radios and other electronioc items).

I've got an article about this on my home PC. I'll hunt it down and post it on my website when I get home from work.

Ron

Landrovers changed to negative earth in 1967 - easy to tell - no ammeter on ones with negative earth. Also coincided with the change to wipers mounted on the bulkhead not separate wiper motors mounted on the windscreen frame. HOWEVER!As you say, it is trivial to change polarity of generators, and I would guess the majority of "positive earth" Landrovers actually in use have been changed by now to use commonly available radios etc - I can't remember when I last saw a dual polarity radio.

Thanks guys, yes it is negative earth !
Does anyone have any idea what the mystery box is below the voltage regulator ?

Cheers,

Peter

Originally Posted by the big fist

Thanks guys, yes it is negative earth !
Does anyone have any idea what the mystery box is below the voltage regulator ?

Cheers,

Peter

Mine has one of them too - I suspect it is a radio interference suppressor - is yours ex-army as well?