I'm not good with electrics at all (not that I'm good with anything else) anyone tell me why on my MK2 fitted with an alternator (Lucas) and halogen headlight conversion and no other extra power devices apart from set of 2 100W driving lights.
WITH THE EXTRA DRIVING LIGHTS ON when you start reving it past 3500 in 2 or 3rd there is a loss of power the engine starts chocking and shaking, the moment you turn the lights off (only the extra driving lights not the headlights) its all back to normal again, lights on and she's chocking again. It seems reasonable that as the crank turns faster the dizzy needs more power, but should the effect of a single set of driving lights be so significant and immediate?

Now its clear that the alternator isnt coping, as you can see a dimming in the headlights, panel lights and courtesy light when the driving lights are on and the indicators where left usualy is faster than the right slow down significantly and work at the same speed. So shouldn't the alternator give me a bit more beyound one set of driving lights? And what's the best alt to fit in a mini to give the extra output?

Cheers

The Lucas alternator should have no problems with running all the electrical system and the driving lights. It is probably on the way out. That or the regulator. The only way to solve this is to have your charge rate checked by an auto sparky. It only takes about 5 mins and they usually do it for nothing.

That way you will know where the problem lies. I had a lucas on my last mini running two sets of lights, no problem. My current mini also runs a lucas with no drama.

Bob

It Might possibly be a bad earth too - if that's the case the charge voltage may show normal, but the sytem cannot carry the required current.
Check all the connector to see that they are clean i.e on the alt. and undo/clean the earth strap, battery terminal etc

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Ben

I had a Lucas 15AC alternator on my 1970 MiniMatic originally, same as the MK2 S had. Lights were always pretty dim. A check at the battery showed it only putting out 13.2 V max, even with a new 4TR regulator- and the alternator had had brushes, slip rings, and bearings.
By the way, new 4TR Lucas regulators were still being sold a little while back- Lucas p/no is NCB148.
Finally I gave the whole lot away in disgust..
I find the later ones (15ACR, 16ACR) Clubbie ones with built in regulator are much better output, easier to find and more reliable.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Where's a good place to find one? As I said I know crap all about alternators.

I bought a new one from Mini Car Clinic for $190 last year.

You can also try an auto electrician- many have recond ones.

Or pull one off a wreck, get it recond if it needs it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.