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Alternator or Dynamo
Posted: Tue Dec 01, 2009 10:47 am
by Sarge
After a small fire behind the dash caused by a short from a trapped worn wire, and lots subsequently melted wires, I have got a new loom for my '69 MM. Unfortunately, the web site I bought it off wasn't too specific about whether it was a loom for a MM with or without and alternator. Of course, I got the wrong one !
Only about £70 for the upgrade, so could someone please enlighten me :
1. How much hassle is it to fit an alternator
2. What are the benfits ?
Thanks
Mark
Posted: Tue Dec 01, 2009 11:01 am
by LouiseM
This thread should answer your queries and also includes a wiring diagram:
http://www.mmoc.org.uk/index.php?name=P ... or+fitting
Posted: Tue Dec 01, 2009 11:57 am
by Sarge
Thanks.
I think on balance, I will stick with what I have. I have no "extras" and haven't had any issues with battery charge.
Posted: Tue Dec 01, 2009 4:56 pm
by billlobban
I'l say this while Roy is on holiday. If you do a lot of driving in winter traffic fit an alternator. Cheap, reliable and lets you run everything heater, lights heated rear screen etc.
Posted: Tue Dec 01, 2009 6:02 pm
by MarkyB
I'll say that dynamos are as tough as old boots, still work after an EMP strike and can normally be fixed by the side of the road with a set of brushes.
Wherever Roy is

Posted: Tue Dec 01, 2009 7:18 pm
by charlie_morris_minor
billlobban wrote:I'l say this while Roy is on holiday. If you do a lot of driving in winter traffic fit an alternator. Cheap, reliable and lets you run everything heater, lights heated rear screen etc.
i think you would be safe even if roy was here.. it is one of the mods he likes provided if i recall correctly you do not pay more than a pound for the alternator.
i would go for an alternator every day of the week.
Posted: Tue Dec 01, 2009 10:35 pm
by mike.perry
The choice is between an alternator or a dynamo + starting handle
Posted: Tue Dec 01, 2009 11:56 pm
by bmcecosse
Definitely - if using the car 'every day' - then get hold of an alternator - and definitely £1 is plenty to pay! Dynamos are fine for summer use/week-end only cars - no need to rush into changing - but if struggling through winter traffic - you will NEED an alternator!
Posted: Wed Dec 02, 2009 11:00 am
by mike.perry
An alternator would look well out of place in my Series MM so it is a dynamo, starting handle, the largest battery that will fit and a charger on a bracket in the garage next to the car so the leads stretch onto the battery. Also the drive is on a slope so that I can push the front wheels out of the garage, jump in and bump start it down the drive.
The Traveller has an alternator.
Posted: Wed Dec 02, 2009 4:51 pm
by billlobban
Mike you could always invest in one of those scarily priced things that looks like a dynamo - spent less on my engine.
Posted: Wed Dec 02, 2009 5:41 pm
by carlosramalho
Billobban,
could you give me more details about the things looks like a dynamo??
tks and cheers
Posted: Wed Dec 02, 2009 5:48 pm
by billlobban
Carlos it's called a Dynalite (Moss Part No PT10802) at an amazingly affordable price of £389.95

. Looks like a dynamo but actually is an alternator.
If you havn't got a Moss catalogue yet -m get one. Makes a good parts manual.
Posted: Wed Dec 02, 2009 5:58 pm
by MarkyB
Good grief, you'd think that people haven't been driving Minors with dynamos for all these years without problems.
Only Minors supplied to the police had alternators fitted as standard to cope with the radio transmitter.
Posted: Wed Dec 02, 2009 8:40 pm
by MikeNash
If you're going to stick with the dynamo (and I'd say why not?) then I urge you to fit an ammeter which is by far the most useful instrument you could have. Then you'll see when you've the big discharge which might get you in trouble and be able to shed load by turning things off.
I ran for years with extra spot and fog lights etc without trouble but, of course, the ammeter warned me of deficiencies. Regards, MikeN.
Posted: Fri Dec 04, 2009 10:17 pm
by mike.perry
My C39 dynamo will just about cope with the wipers, heater and dipped halogen headlights and short periods on main beam plus a pair of driving lights. The car has an ammeter fitted.
Posted: Fri Dec 04, 2009 10:30 pm
by bmcecosse
There are more powerful dynamos available of course!
Posted: Fri Dec 04, 2009 10:59 pm
by rayofleamington
i would go for an alternator every day of the week.
I'd stick with the bullit proof dynamo - that saves the need to replace the flaky alternator every day of the week.
Until I got older and generally busier, my Minors were all daily drivers. I gave up eventually when doing 20,000 miles a year in the (very tired) Minor meant fixing it every weekend. After changing the gearbox 3 times (including rebuilding one with new parts) led to yet more gearbox problems I was due a break.
Most of the modern cars I've had needed their fair share of fixing too, but at least they're disposable. Given the choice between an early Vectra and a Minor, I'd say the Minor was less hassle!
I've lost count of the number of failed alternators I've had on modern cars. I've had 15 Minors and some had alternators - all of which failed. Dynamo's win every time - and over winter I used to put the battery charger on ovrnight every couple of months and not had to worry about short runs with lights, heater and wipers on.
These day's I find solar chargers to be a better alternative, as my cars have had to sit around lonely and unloved for nearly well over a year.
Just a tip - these days people are lazy / badly trained and will sit in all ques, junctions and traffic lights with the brakes on, rather than the handbrake. The brakelight current adds up to nearly another headlight... and with a dynamo you're not producing enough power when the engine is at idle.
Posted: Sat Dec 05, 2009 11:09 am
by bmcecosse
Strange Ray - you say "stick with bullit proof alternator" at the beginning - then slag it do death !
Posted: Sat Dec 05, 2009 3:09 pm
by rayofleamington
Strange Ray - you say "stick with bullit proof alternator" at the beginning - then slag it do death !
I think you must have missread - I've had lots of daily driver Minors and the Dynamo ones all worked fine (although I did have a broken brush-spring on the SII trav). The few Minors with alternators ALL failed on me.
Dynamos are rather like drum brakes - you need to remember you have them, and all will be fine. Alternators, unlike other 'upgrades' are far more likely to fail on you.
Posted: Sat Dec 05, 2009 3:15 pm
by bmcecosse
Read what you wrote Ray! I'm sure you meant to say 'dynamo' - but at present - it reads 'bullit proof alternator'!