Morris Minor Owners Club

I want to update my cars charging circuit. What is the easiest and how do i do it but what would give the best results. i have 2 options simply positive to negative earth or go for an altenator conversion.

Changing the polarity will not give you any obvious results, just a little less corrosion on the terminals and the ability to run modern accessories. An alternator is the only way to increase the power output

How easy is the altenator conversion.

If the car is running OK with a dynamo and the battery is charging then why mess around with it?

I would like to modernise her as she is my everyday car. as such i would want to change polarity to negative earth so if an altenator conversion dose the same with extra benefits how easy is it.

ESM do an Alternator conversion kit ALT 100 for £60 , it is designed for a negative earth car.Other suppliers sell the kit.

So you need to re-polarise the car to negative earth first and then put the alternator on.

You may need different length main battery cables, remember that you are going to be connecting the
negative post on the battery to the body work ( black cable or braided unsheathed strap ).The new positive cable ( red
cable) will connect to the solenoid.Out with the tape measure.

Search on previous posts for " re-polarising " and refer to the Alternator wiring diagram at the start of the Electrical section
of the forum.

If you want to go scrapyard searching, ESM's parts diagram will help you in the search.Again previous posts on "Alternator "
will steer you in the right direction on what to look for.

Everybody will have assumed that the existing wiring loom is in reasonable nick to start with.If not and you are starting afresh, then you will need to advise the loom supplier of all the wiring upgrades you require ( or are likely to need in the future ) at the time of ordering including an alternator.

Bob

Have looked at the diagram at the start of the electrical section and it appears to only be half the diagram

Robbiet9999 wrote: it appears to only be half the diagram

Well, it doesn't show all the existing wiring that needn't be disturbed, such as the other wires connected to the ignition switch. Is this what you mean?

Kevin

No the red and blue wires just go off the edge of the page where do they connect to.

if using Internet Explorer 8 or 9, try reducing the size of your screen - look in bottom right of screen and click on the arrow next to the 100% - go to 75% and you should see the whole picture

Ok sorted thanks makes more sense now

If you are unsure what to do, I would strongly recommend one of the conversion kits available. I did mine last week. I got mine from Morris Minor Centre, Birmingham. The kit comes with everything that you need, except the new battery terminal and cable. It was very easy to do and worked first time.
A few personal preference points that I would raise are;
1) They tell you to cut back certain wires to the loom, that is fine if you are sure you are doing a permanent conversion, can't think why, but the next owner might want to revert back. So I just taped mine down.
2) They also tell you to remove and cut back some wires and join together others from the regulator, so you can remove it. I think it looks better left where it is so I only pulled off D&E, taped them over and tucked them out of the way. E is earth so pull that off and connect to the body using a ring connector and self tapper. Leave wires to A1 & A , you are now just using the regulator as a connector.
3) I think the coil looks better where it is so I made a bracket, fitted it on the alternator fixing point and fitted on there. You can't use the original fitting strap.
4) Alternators only work with Neg earth. So turn the battery round, connect up the new Neg. earth terminal.The pos and neg terminal ends are different sizes. Swap over the two wires on the coil . The white/black wire should now be connected to the - or CB side of the coil. When fitting the retaining bar on the battery make sure the it cannot slip and short across both posts. If necessary cut two 'U' pieces out if it to be certain.
I can assure you it has taken me longer to type this out than it did to do the job.
Good luck

Robbie
Didn't mean to leave you in the lurch, sorry.Tuesday was a 13 hour day baby sitting and this morning was helping a pal
strip down his brakes on a 1936 Morris Tourer.
I see DavidJay ( and others ) has done a fantastic job in advising you and very much hot off the press, as he only did the job recently.
Bob

You should join wires A and A1 together. Also clean the dizzy points and the fuel pump points or they will give trouble down the road. An alternator from the scrappy works perfectly well - no need to pay fancy money for one ! I buy all I see at £1 each......