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MG Midget and Sprite Technical - Alternator Conversion

I know there is lots in the archive about this, but some of the information is very confusing so can somebody tell me if my connections are correct please. See attached picture.


IAN Pickering (68 Midget) Getting There!!!!

Hi Ian.You're nearly right!The easiest way is to join the brown/green and the small brown/yellow at the regulator(this is now the warning lamp circuit),put the brown/green at the alternator on the small terminal. Join all the browns and the large brown/yellow at the regulator and insulate well!-put the brown/yellow to one of the large terminals at the alternator.Run a new piece of wire from the remaining large terminal at the alternator to the starter solenoid post(battery side).I usually remove the regulator altogether as it makes a neater job.Start the engine check the warning lamp goes out and you have approx 14.2 volts at the battery.This assumes you're using a Lucas ACR or A127 type alternator. Hope this helps ,regards Steve.
Steve Smith

Thanks Steve Will make a start now
IAN Pickering (68 Midget) Getting There!!!!

Google "Dynamo to Alternator" and you will find an explanation by Keith Calver that uses / retains the regulator as a junction box.
Alan Anstead

Can anyone tell me the connections for a later style control box, my letters aren't A A1 F D & E!
Nick

if you dont have A1, A, F, D and E

you might have E, D, W/L, F and B

B is the same as A on the other Control Box (B = battery)
D is the same (power output on dynamo)
F is the same (field terminal on dynamo)
The main difference is that the smaller type has a separate W/L terminal instead of taking its feed to the W/L off the smaller of the "D" terminals

E does the same

I think the settings are different but as I dont have one to worry about...

I shan't

HTH
Bill

Google Racemettle dynalite for a wiring diagram for this alterantive regulater.
Alan Anstead

Busy with alternator conversion on 60' Frog. Followed recent threads which must be for midget or later Sprite. My problem is that the wiring colours on the Frog Eye are different: at the regulator, I have one Blue/brown, one thick and one thin brown, one yellow/green, one thick and one thin yellow and one black. This is as per handbook wiring diagram which is one more wire than the recent threads. Will be pleased to know how to connect this lot up. I have gutted the regulator, alternator is mounted and wired to solenoid and polarity changed to negative.
ALTARTANFROG

much easier way...

get a single wire GM Alt. with built in electronic regulator....throw away old reg box, connect the big brown wire to the 2 smaller brown wires, hook up a volt meter gauge and get rid of the idiot light,
(put in a toggle switch in it hole for something cool...aka fog lights)

connect the single wire from the alt. to battery side of siloniod, cap and tape off all the other wires that used to go to the reg. box....fire up the car cause your done, happy driving!!!


prop
Prop

Al TF
if you have gutted the internals (or at least disconnected the coils from their terminals) you could solder a connector between the F, A and A1 terminals inside to allow them to look normal and take on the jobs which an alternator requires.

Basically just to connect the ignition switch to the power supply by feeding the alt output to the solenoid and wiring loom as in the modified wiring diagram I've posted

very easy and will look authentic to the Non Concours judges eye

The yellow wires are what the Frogeye uses as its warning light circuit and can be left as in the diagram. The stator coil will energise when the ignition is switched on and turn on the alternator via the D terminal on the control box.

I think this will answer your question, if I have anything wrong there will be some better advice along in a while.

There are many ways of dealing with this situation, I simply removed the control box and fed the brown wire on the fusebox (later style car)off the solenoid and took off the redundant wires from the loom.

Prop, GM alternators in Yurrup tend to not fit the standard engine mount positions, being mostly based on Vauxhall/Opel engines which have a solid block and rubber insulation method of connecting

On this side of the pond we are better sourcing Ford, Bosch or later Lucas type alternators




Bill

Bill, thanks for your knowledge and diagram. I have it wired up now and it seems to be OK with no smoke!
AL TARTAN FROG

Yeah, I know what you mean bill,

it took me several days to figure out how to make a mount for the alt, to fit the 1275, but I have never been more happier with doing this conversion, cant imagine still using a generator and mechaincal regulator box..

prop

Prop

This thread was discussed between 03/03/2008 and 15/03/2008

MG Midget and Sprite Technical index

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