View Full Version : Austin A35 engine electrics, esp generator

08-21-2005, 03:29 PM
Hello, recommended to this site from UK Austin site.

My engine is an Austin A35 A-Series, 848cc, circa about 1968. I'm posting here because from all the manuals, it seems to be basically a Mini engine, with the exception of the transverse location and gearbox.

Ha ha, but the engine is located inside a 30ft trimaran, in Wellington New Zealand. I bought the boat with engine a lump of rust and dead, have lifted it out and totally restored it. It looks beautiful now, and theoretically at least should start. If only I could connect the electrics!

The origianl manuals show positive earth setup, so that's what I have wired it up as, but it looks simple to just go with negative ground also. Everything is in place - voltage regulator, coil, distributor, generator.

My question: The original Lucas generator in the manual looks nothing like what I have, which was fitted later (also Lucas, more modern though). There are three spade connectors - two large, one small. I'm guesing the small spade is for the charge light, and that one of the big spades is either neg or pos (depending on my setup) and the other is earth. Trouble is, I can't tell which! Any help?



08-21-2005, 06:26 PM
Marine electrics are, generally, different from automotive electrics. Generators and starters spark. Not a good thing in an enclosed environment like an engine housing on a trimaran. I'm not surprised that your generator looks "different". They are, most likley, sealed units. This helps reduce explosions (flash fires) if there should be petrol fumes in the compartment.

Are you sure your "gernerator isn't really an alternator?

If it is an alternator, here's a link to help you understand what the terminals are.
Alternator Info (http://www.mgb.bc.ca/service/understand-alternators.php)

08-22-2005, 04:06 AM
Well done, Jedi peron. I note you too live in a city called Wellington.

Quite right, I have an alternator not a generator. Heres a link to a pic of the same model: http://www.lucaselektrik.com.tr/picture/alternator/23985.jpg

Do you think I should perhaps go straight to neg earth setup? Theres an article in here on that, should be easy.

Either way, an idea on which connector on the altnerator is which.


Wellington, NZ

08-22-2005, 09:18 AM
Try and identify that alternator before you do anything else. There are VERY FEW positive earth alternators. Almost all Lucas units are negative ground. Don't turn on the ignition or try and crank the engine over until you've sorted this out... or you might be buying a new/used alternator anyway.

Tell us about the voltage regulator. MOST of the common Lucas alternators use an internal regulator. There are a few from about the period your engine was built that use the external regulator.

Were it me, and I wanted a reliable charging system, I'd substitute a later alternator (non-Lucas). You can opt for single-wire hook up types with no charge lamp for the dash (a volt meter is recommended), or you can get a "standard" type which requires a charge indicator lamp to be part of the field coil circuit. In the U.S., Delco/GM alternators are a common conversion. Other people have used Bosch units. I have a Motorola copy of a Bosh alternator.

Good luck, let us know what you decide to do.

08-22-2005, 03:21 PM
It seems I must go with negative earth setup, all the signs point that way.

My voltage regulator is a Lucas unit that is original to the motor and sits externally, taking both wires from the generator (in my case the alternator, which has three wires, hence the confusion).

I know that this setup worked for years, and I'm keen to at least start the engine.

However the last post makes a lot of sense. Reliability is very important at sea. Typically the alternator will be charging two or more batteries.

I'll research my alternator and see if it is internally regulated. If so, I'll go with a simple neg setup, omit the external VR, run the engine and then think about upgrading the alternator. I have a volt meter built into my boat dash.

Many thanks,


08-24-2005, 09:48 PM
As a matter of fact, my A30 came from YOUR Wellington! A nice little Estate Wagon and is a testament to the "no rust" New Zealand legend.

I have a 1 wire GM alternator on my Mini, I guess that's Holden to you. It didn't take much to get it to fit: a little machining (using a spade drill) off the case to get the pulley to line up with the water pump and harmonic balancer and a twist of the case to get the rear mounitng hole to align. GM 1 wire units are inexpensive here ~30.00 USD. I have the indicator light feature installed, making the alternator a 2 wire unit :>}


08-25-2005, 11:26 AM
My Mini is also a New Zealand Mini....no rust!