Alternator Series to Stage One Compatabilitiy

[firemanshort]

Off hand... does anyone know if the Stage One alternator is the exact same as the Series III? Are the amp ratings the same?

The follow up question is, does anyone know why the current would change while the engine is running at constant speed? For example, I am driving down the road and the headlights are burning white bright. Then the dim down just a little - like I just turned on some high amp draw appliance in the cab (but it is a Stage One and there are no appliances in the cab - not even a radio). They change back and forth but spend most of the time on the dimmer - more Lucus appropriate setting.

I am wondering if the internal voltage regulator is going bad. Then I wondered if it had an internal voltage regulator in the first place. But then I think it just may be LUCAS and in the switch.

Any one?

[map1275]

The basic design/model; is the same but the hand is different I think.

17ACR or LRA100

Stage One is LH mounting Mini etc. is RH. There are two other Lucas alternators that will directly interchange and have higher outputs;
A115
A127 ??
Both use the same plug but are also handed.

You need to test the alternator's output instead of guessing. A voltmeter will do what you require.
If nothing else is affected, I would suspect it's a dimmer switch problem or similar.

[disco2hse]

There are a number of alternators used on the Stage 1. Amperages vary from 80A- 120A and it may be 12V or 24V. Of course when you "exact same as the Series III", which SIII are you referring to? The 4 cylinder, 6 cylinder, diesel,...? Have a look in the "Series 3 Optional Parts Catalogue Part 2" in the Manual Downloads section.

Also, have a look at the wiring diagrams in "Series 3 Workshop Manual V8 Supplement 3" in the Manual Downloads section if you haven't already bought a copy of the book (which I would recommend, it is cheap enough and readily available). Most configurations are listed except military and specialist applications.

So far as dimming is concerned. That is a sign that something is not right. Could be a range of things that cause drop off. I would suggest a voltage change as a place to start, possibly a dead short somewhere. Time to get the multi-meter out, or sniff around for the smell of burning plastic.

Does it dim if you are standing still or only when driving?

[firemanshort]

I have never sat still in it long enough to notice the lights changing brightness - I have just noticied it recently when driving at constant speed.

The stuuupid charge light almost always flickers when the engines gets to idling real slow - it has been like that since I got it. hey... maybe that is one of them things called a 'clue'.

I was thinking if the alternator was the same as the Series III petrol then I might consider the DELCO 10si conversion that is real popular over here in the States. It appears that it may not be that simple - or it might.

i will break out the multi-meter this weekend and poke around to see what numbers show up.

[map1275]

The engine bay picture in your link isn't very clear but you appear to have the standard 35 amp (18ACR) unit.

These are readily available in the states as they suit countless British vehicles including some Ser III. Hand is the issue, plus the V8 has one extra (small) wire from the alternator in addition to the plug. I forget what this is for off hand (Moss Mini Mania....).

If your car is idling slowly, then the charge light will flicker or may even stay on. This is what they are intended to do to prevent discharge. As soon as revs pick up it should go off.

[disco2hse]

Yeah. Sounds like the alternator is fine so you need to look elsewhere for the dimming lights. Do you have a split charge system?

[sebking]

"plus the V8 has one extra (small) wire from the alternator"

would love to know what this is for - The Alternator I have is obviously not right as it is a Delco (will check what model) and there is a small brown wire just hanging loose.

Seb

[disco2hse]

Seb, don't worry about it. If the battery is charging the alternator is doing its job.

So far as the W connection is concerned, umm, it can be used for a number of purposes e.g. copnnect your tachometer to it to get your rev count. On mine that is coinnected to the vehicle's split charge system and acts as a circuit feedback, I think.

I have a 24V Bosch on mine so it will be different. Best thing is to have a close look at the circuit diagrams in the manuals in the downloads section to se if the connection matters.