I make sure I have a 'BIG' Battery measured in Cold Cranking Amps for every vehicle...and I take a spare Alternator & Fan Belt on all trips in a Mini...and some fine wet/dry paper to clean connections & dielectric grease for reassembly.

Rarely have I been disappointed by a service stop but MS in Adelaide takes the cake...we have driven nearly 3/4 of the way around Australia and the battery is either failing or not getting a sufficient charge and I need 2 new tyres, so please do a service too.

Wouldn't let me anywhere near the Mini - and I've got to get it to the finish line after 70 days - oil/filter & lube done, new tyres mounted/on and, "we tested your battery and it needed replacing".  New battery installed.  Here's your bill.

Brilliant, the buggers put a 260 CCA battery in the Mini suitable for 'antique cars'.  Bloody thing was flat when the Mini was landed on Canada's shores.  Out with the MS 'mistake' and in with a 560 CCA battery. 

A common conversion when converting to alternator on the Mini is to leave the regulator in place but switch the wires around inside so it looks the part but is not functional. Open it up and see if that is the case. Remove your alternator and take it to one of the parts stores they will test it for free.

Its helpfull..........

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Sorry to bump such an old thread, but my 1960 Morris Mini Minor just died and it happened so suddenly while driving that I'm inclined to believe it's electrical.  My car has an alternator installed and still has the Lucas regulator hooked up.  So I'm thinking this might be my problem.

First question, any more information on this limp-home bypass?  Like which wire to move.

Second, any way to test the regulator to see if it's the culprit?

Another thing is internal corrosion in the cable. It happens, is hard to t-shoot, but does not sound as if this is your prob at the moment, with what u describe. Typically this causes a an immediately prob.

Also check the main battery cable is not shorting on the exhaust system underneath the car, as you started the car (max load) and only drove one mile it sounds like something has possibly shorted out.

Good point N.J., I've seen these problems arise from something as simple as a bad battery connection. Once the connections were cleaned the problem went away.

Cleaning the connections, getting the battery checked, getting the alternator/regulator checked- all are generally no cost and the problem will likely be found somewhere in there.

USNSkiroy- let us know what you find, hope it's an easy fix.

Interesting. I went to a tech seminar on batteries just this morning! The answer to the question you asked is "No. The car's electrical system runs off the battery. The alternator is there to replace the energy released to run the car." Batteries are like fruits and vegetables...they start deteriorating from the start. Proper charging just slows down the inevitable process. Heat, cold, and vibration are enemies.

Taking off from MacAngelo's note, my personal experience trying an after dusk push-start of my alternator-equipped Mini with a nearly dead battery created an amazing light display at the tailpipe as unburned gas lit off there instead of in the cylinders. I'd installed aftemarket gauges and eliminated the charging light. I didn't know that it has to be there to 'excite' the alternator diode(s), allowing the alternator to fire up and charge the battery properly. I'd run off the battery alone for several months (weekend use).

While a bad alternator could be the underlying culprit, it could be as simple as the battery reaching the end of it's useful life. As QS alludes to, low voltage in modern cars, especially the ones with inherent drain to to run all the electronics, will play havoc with all systems. I watched the gauges in my '02 Sonoma whip back and forth and blink on and off as the battery died. I barely made it to the shop to get a new battery.

Without getting into esoteric details (2.11V per cell, X 6=12.66 volts @ full charge, etc. etc.), a battery reading 12.2 V or less isn't good. 10 or 11V is a door stop.

NAPA or Advance Auto or nearly any parts store will run a free battery check which will tell you the voltage produced, the CCA/CA left in the battery, how that compares to the battery's rating, and if it's below typical parameters. If the battery is checked in the car, it can also diagnose the charging system.

Use the 'KISS' system here.

Simple, direct and free.

It has been my experience on my Mayfair Mini (whatever year it is) that it needs a fully charged battery and an alternator in good working order to operate. Same on my 740iL which needs a specific voltage (more than 12 volts) to operate.

I had this exact thing happen on a Volvo once. The problem was a worn wire insulation somewhere between the battery and the alternator. The drain emptied the battery, the alternator had no output, the lights got dimmer and dimmer, the spark got weaker and weaker manifested by the car going slower and slower despite full throttle. Finally  kaput. With my size short-circuit, it took 30 min to progressively kill everything. Your mileage may vary

MacEwen touched on this a bit, I go into a little more detail...

Alternators have no permanent magnets installed, so they require some DC power source to energize the magnetic field before they can start producing more electricity, the battery or a jump start will take care of this. Sounds like your alternator quit and the battery was drained low enough (headlights suck some power) where it didn't have enough power to spark the engine.

As a result the battery was also drained low enough where it didnt have enough power to energize the magnetic field on the alternator... Unfortunately in that case popping the clutch with the car rolling down a hill won't do the job because there isn't any DC power from the dead battery to energize the field coil in the alternator to get the entire process going.

If the battery dies and the car is running with a working alternator, the alternator will continue to function and the car will keep running because the alternator is powering its own magnetic field- but all bets are off once you shut it down.

Fix/replace the alternator, get a good charge on the battery and I bet it will run just fine.

Good luck!

Let us know if your car was still using the old Lucas voltage regulator.  Not sure about 1970, whether a 1970 car had an alternator with an internal regulator or not.  A lot of older Minis that previously had generators get modded to alternator, its easy to add an alternator while leaving the old voltage regulator on the bulkhead, that way no big changes to the wiring harness. But it can lead to problems.  The old two-bobbin regulators can get so much current from an alternator that internally the rivets overheat, melting into the plastic, which makes the rivets come loose from the contacts (the rivets are what connects the contacts on one side of the plastic to the other side of the plastic) and then the car dies.

I am guesssing that whatever was supposed to regulate your alternator quit working.  If the regulator was giving your alternator even a little field current, then normally, spinning the alternator would make enough output current to run your ignition and lights.  Just FYI, if the Lucas regulator did go kaput, you can put it into limp-home mode by moving one wire over, directly connecting the ignition wire to the field wire.  The terminals have extra nubs on them so its easy to double up connections. This forces the alternator ON all the time, no regulation, just drive home with the lights on at gentle revs.

In the meantime, remove your alternator and take it to Pep Boys or Advance or NAPA, they will give it a spin check and tell you if its still good.  The slip ring brushes may have died, that would also cause no output, but that's an easy repair.

 

Might be wrong here, but I'm pretty sure you need a charged battery.. If the alt isn't charging then the battery dies, and there goes the"spark" for the ignition. Older motorcycles used to have magnitos that provided a spark each time the engine turned over, but this is not the case here. Check the alt, and install an ammeter to monitor the battery charging or discharging.

Hello again,

I swear this new car likes to be difficult. I posted recently about the fuel gauge and found the float sinks here and there. I got the original horn working, and then the wipers and turn signals stopped. I troubleshot and found the culprit to be the fuse block, so fixing I did. I was excited for tonight because I was going to wash it and go for a cruise, and the washing went off without a hitch, but I left the wash and not a mile after I noticed a studded from the car. I was miles from home and figured to pull out a little more choke, but my lights kept getting dimmer and dimmer. Luckely at the top of a giant hill she died. Rolling down the hill with no lights, and no engine I pulled into a residential area. I waited, twiddled my thumbs, pulled the harness out the back of the radio, waited some more, tried to push it up another hill, whipped it around, rolled down the hill, poped it into gear and gunned it to get the final mile home complete, and conveintently had a mini van pull out in front of me doing 15mph, and there I was screaming profanities only for my ears with my dieing car. It's a 1970 Morris mini and it has an alternator on it, but in all my experiences with cars even if the battery dies or is disconnected the alternator still keeps the car running, so why does mine seem to die? Does the alternator on your cars keep it running even with no battery. 

Thanks for even more of your help.