Morris Minor Owners Club

Matt wrote:I *think* that might be triumph 1500 unit, ala 1500 midget

Manifolds and ignition are the other way round on the Triumph boat anchor, and the rocker box is held on in a very similar way to the A series, so it's not one of them.

If it was, I'd be more worried about bottom end self destruction than a trivial bit of flame... ;)

Picked up another regulator for $20 (australian), going to put it in tonight. The electrician couldn't think of any reason for it to catch on fire, im pretty confused too. Anyway ill hook this new one up carefully and see what happens.

well i put the new regulator in and ran the car for about 10 seconds and the damn thing was already overheating again so replacement didn't help. If its overheating that quickly could it be that voltage is going in and not going out? Certainly will have to check the wire to the battery.

The regulator is a Lucas 15ac

Ok now im really confused because this just doesn't seem right to me. The alternator has 3 connections. It has Aux + which is running from the alt, through the regulator, through the fuse box and then to the ignition ??? this doesn't sound right to me!

There is a IND connection running to the indicator light (makes sense)

and there is a "+" connector which goes to the (i may be showing my ignorance here) the starter motor.

Does this sound completely wrong? The regulator shouldn't be going to the ignition should it?

Is the battery definitely connected in a negative earth configuration?

The regulator controls the output voltage by varying the amount of current going into the field winding (when the battery voltage is too high it switches off the winding and the alternator stops working). It should only be powered up when the ignition is on or the alternator will quickly flatten the battery.

The main output should go to the battery, usually via the battery terminal of the solenoid (not the starter terminal).

I suppose the field winding in the alternator could have melted - that would mean the regulator was feeding into a dead short.

So here is what i have come up with.

The guy had the aux + going to the regulator then powering all the aux gear. Part of my aux gear is a voltage meter which returns to the battery. The voltage meter shows no charge thus i think that there is a bad connection and charge isn't getting back to the battery. Due to his dodgy incorporation of the regulator into the circuit it kept getting power pumped into it and couldn't got rid of it so it overheated.

I'm going to rewire it so that the + terminal from the alternator goes through the regulator and then to the solenoid which in turn feeds the battery.

As far as aux power goes i will tap into the + wire after it goes through the regulator. This way i should be getting a regulated current to all areas of the car.

How does this sound, should i incorporate the aux terminal into the system?

I'm afraid that doesn't make any sense at all. The supply to the regulator and the voltmeter should be from the switched side of the ignition. The voltmeter should show the battery voltage when the ignition is switched on regardless of what the alternator is doing. Don't feed the main output of the alternator through the regulator! It's only designed to regulate the supply to the field coil.

EEK! Right i think ill get a pro to look at it! Thanks for the help!

I assume you are down under (no location filled in) and as the Datsun conversion is very popular over there its probably worth while contacting the owners club over there as they may already know of this type of problem and the solution.

None of what you are saying is making sense -but then I know zilch about Nissan alternators! Personally - I would dump this whole dodgy alternator and regulator - and just fit a straightforward alternator with all the regulator etc inside! Then all you need is a hefty mains cable from battery +ve, and a little cable from the INDicator light. So simple, and usually low cost for a working alternator from scrappy.

Talked to an auto electrician who basically said that the alternator must be stuffed, something to do with rotors (i forgot the exact explanation quickly). But his answer was to swap it with a new alternator. So i got one with an internal regulator which ill try and fit tonight.

Other people though it must be a short, but the auto electrician was pretty certain that that shouldn't cause the regulator to overheat so badly.

Ok got another question (surprised?)

I have chucked a new alternator in. The new alternator has the terminals B+ D+ and a D-

The B+ is obviously the battery

Would the D+ be the indicator light?

I have no idea what D- is, it doesnt have a spade connector or anything.

Normally just the two connections - heavy cable to the main +ve bus (usually brown) often connected with a large Lucar spade - and smaller connection to the IGN warning light, usually a small Lucar - this should be a green wire with perhaps a yellow tracer although there have been some variations of the tracer colour over the years. Nothing else required for self contained alternator.

Awesome, thanks. I'm 100% sure about the battery connection so the other must be the ind light. Unfortunately i need a slightly bigger V belt now so ill have to fit that tomorrow. Grrr.

On the rangey have just such a terminal off the alternator that goes nowhere and isnt on the wiring digram ! Heaven knows what its for - spent a long time when having problems with it wondering if it had lost a wire - problems solved and it hadnt.

"D-" is an earth connection, for use where the alternator body isn't earthed via its mounting. It is linked to the alternator casing.