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MG Midget and Sprite Technical - HELP Wireloom

Hello,
I have tried to put an alternator on my negative earth MKI midget.
The fact the wireloom is intensively transformed by the past, and it is very difficult to recognize each wire: not pluged, colours change etc...

So after the transformation of the regulator box and reconexion, the black wire puged on E blade of the regulator burnt approximatively on 30cm and damaged other wires.

So I have to change the wireloom.

As my midget is negative earth with alternator, with ignition with the key, solenoide without cable to do the contact, electric revcounter, electric fuel pump, etc...
The car is very different from an original GAN1.

So I ask myself if it will not be easier to put a new wireloom from a GAN5 allready adapted to the alternator?

laurent
ld derancourt

laurent

I have attached a small drawing of how the original Midget should be wired. Normally this is pos earth, so you need to imagine this drawing with the battery simply reversed and made negative earth

The easy way to fit an alternator is to:

The wire that connects from D on the voltage regulatorto D on the dynamo now needs connecting to the SMALL terminal on the alternator

The wire that connects to the F terminal on the voltage regulator now needs to be made bigger and connected to both the large terminals on the alternator and then connected to A on the voltage regulator.

Connected in that manner it should work correctly

If you can understand simple electrics you will notice in reality that when connected in this manner the large connections on the alternator are connected to the positive of the battery and the small connection is connected to the opposite side of the ignition lamp to the wire from the ignition switch.

Please do not hesitiate to ask further if this is not clear


Robert (Bob) Midget Turbo

Thanks Rob,
I have dismantled the regulator and welded A A1 and D together.
And I have welded E and F together.
Do i have to keep this transformation?

The black wire from E on the regulator was a small wire and has burnt. I think it is the wire pluged to the earth.
Normaly this wire is also connected to the earth on the oil/temp geauge with two other black wire.
Under the dash, those 3 wires are not screw on the earth. They are in the air.

I think I have to check all the wireloom to be sure what is pluged and where.
laurent
ld derancourt

why did you do that??

You must unweld the connection in the voltage regulator between the D terminal and the A and A1 Also the connection you have made between E and F should also be removed! What have you got connected to the F Terminal?
Robert (Bob) Midget Turbo

Laurent,

I would presume from the context of joining electrical items that the actual term you want is solder rather than weld. IIRC the french verb soudure translates into both weld and solder, and I assume braze also, weld is appropriate when the parent material being joined is melted, solder when a lower melting point material is used to join the parts without melting the parent metal such as a Sn/Pb alloy.

Please don't take that as a criticism, just information. I came across it originally when working in Lausanne on occasions.
David Billington

Rob,
Why? I have used a method given by Keith Calver seen here in the archives.

David,
weld-braze, I don't know, but with my small electronic knowledge and tin to join the blade and the wire.

ld derancourt

I was aware of that David but thought it easy to speak in Franglais! :-))

I am wondering if Keith was refering to the later voltage regulator? I assume yours is the RB 106?

If you wire it as described in my first post then it will work. The connection you have made between E and F has caused a short and thus the earth connection on the F terminal is burnt! What wire have you conneted onto the E Terminal? I am suspecting you have it connected to the big terminal on the alternator? If so then lots of smoke.
Robert (Bob) Midget Turbo

Rob,
my regulator is the one with the wires screewed on the regulator A A1 F D E.
on F I have pluged the brown/green wire from (I think) the dynamo
on D, I have pluged the big brown/yellow wire from (I think) the dynamo
on E I have pluged the small black wire, connected to the earth and the small brown/yellow wire (charging bulb?)



ld derancourt

before the transformation, I had on:

A1: small blue wire
medium brown wire
big brown wire

A: big brown wire

F: brown green wire

D: big brown yellow wire
small brown yellow wire

E: small black wire


So if I remove the regulator and connect:

wires from A, A1 and F together
wires from D togeteher

brown green on the large terminal on the alternator
brown yellow on the small terminal on the alternator
an additionnal brown yarn between large connection of the altenator and battery side of the solenoide

Is it correct?
And if so, what I have to do with the black wire connected to the earth (the one who has burnt)?

laurent


ld derancourt

I have inspected the loom. The earth wire is burnt on all the lenght to the bulkhead connexion.
The brown green wire from regulator to dynamo was dammaged cause it was in contact with the earth wire.
One think I have noticed is the brown green wire seems to have some damages at the alternator side.
Perhaps this wire is not big enough for the electric power when connected to the alternator?

I ask myself some questions, perhaps you can answer:

Can I replace the brown/green wire with a bigger one (without removing the old one from the loom - just unplugged each side)?

And then connect the wires as written before?

I remove the earth wire wich has burnt
and I remove the regulator from the engine bay.


Could it be the way to test before producing a custom made wireloom?
ld derancourt

Yes you canreplace the brown and green wire with bigger.
If I understand you correctly then your action sounds correct. The burnt out earth wire is not neccessary and can be left out/removed.

I am just going out to work for an hour or 2 so will check when I return and again study the solution you have described.
Bob
Robert (Bob) Midget Turbo

thanx Bob
ld derancourt

Laurent

The brown/green wire from the alternator will have burned the same as the earth wire because you put them both in circuit from alt to earth. If the brown/green is less damaged it will be because the thinner earth wire has less ability to carry the load but the same amount of power went along both wires.

To make the wiring simple, all you need to do is supply a link (let us say BROWN) from the alternator to the battery. For this I use two wires to the solenoid battery connection.
From there you need a brown wire to provide electricity to the ignition switch by way of the fusebox. You need to give power to the fusebox with a heavy brown wire.

To give the car lights you need to provide power to the lighting switch too, my car has a brown and blue wire that does this, off my fusebox at the same take off that works the ignition.

None of the other wires on the control box need to be used and can all be disconnected. The brown/yellow wire needs to be connected to the small terminal on the alternator plug. You do not need the control box to operate the alternator. You do not need an earth wire anywhere except the battery to body earth that is already there.

I hope this helps you


Bill sdgpm

Thanks Bill, but I have two more questions.

the solenoide has got one connector each side, one for battery and one for starter motor.
But it has also two small conectors on the top. On the small top connector on the startermotor side, I have a small blue wire pluged, and comes (I think) from A1 from the regulator.
Do I need this wire?

I have a brown wire wich goes from the A1 to the Key contactor for ignition.
My car fires with the key (4 positions: parking, stop, ignition, fire).
Do I need o plug this wire to the fusebox?

laurent
ld derancourt

I do not know about the blue wire on your solenoid laurent, but wiring for the car needs a feed to the ignition switch to put power to the ignition circuit

I took mine from the battery LIVE side of the solenoid which I fed to the fusebox (two glass fuses type)

this is then fed to both the ignition switch as unfused live power and the lighting switch, again as unfused power.

My diagram shows these as coming off the fusebox before it passes fused power to the horn.

I have drawn the ignition switch wire as Brown and the lighting switch as Brown and Blue

None of the regulator box wires need to be used if you wire it this way. You simply use the thinner Brown and Yellow wire to feed the alternator "ind" (little terminal) This is fed from the ignition "on" circuit with a White wire behind the fascia

Does this help?

All the elements you need to consider are in the drawing, anything you do not has been left off.
Bill sdgpm

The problem with the modification for fitting an alternator is that there are a number of ways to do it. The diagram Bill has posted is the basic way and it is the way that I would do it. However I posted the diagram of how to do it if you keep the Voltage regulator in circuit as you had tried to do Ld

Bill, obviously the wire was indeed melted by a short to earth, I just thought it easier to simply agree with Ld to change it bearing in mind the language barrier. :-))

laurent
I also do not know why the blue wire is connected to the starter motor side of the solenoid, it could have been originally fitted to the otherside to act as a connection to the ignition lamp but probably now it is not required. Again to determine if your fuse box is or is not connected to the ignition positive is simply to try all your circuits and see if they all work. If not then you may need to add a supply to the fuse box as described
Robert (Bob) Midget Turbo

Bob and Bill,
one brown wire goes to the fuse box
one brownblue wire goes to the light switch
one brown wire seems to go to the key contact and then yellow wire goes to the solenoïde to the battery side.
I suppose it is like that cause I have difficulties to follow the wires under the dash and in the wireloom.
the small blue wire is connected to a S connector of the solenoïde.
There is a I connexion on the solnenoïde without wire.

photo to explain it.

laurent
ld derancourt

photo


ld derancourt

Ahh the blue wire is simply there to energise the solenoid for starting. Leave it in position!
Robert (Bob) Midget Turbo

Ah yes Bob the language barrier!

I guessed that was why but thought it better to tell Laurent the lot

his English is fantastic and I wouldnt even be able to start telling him "en francais"

My GAN3 car doesn't have that sort of solenoid so I cannot begin to wonder what the blue wire is doing there, I cant see it in any of the Haynes assortments. Does it come off the ignition "go" terminal, turn the key all the way and have the starter turn? If it is labelled "S" it may well be for that.

Laurent try to start the car wired as I (and Bob) suggest but with the blue wire disconnected. If nothing happens try testing whether the ignition switch makes the blue wire go "live" I would have expected the "start" wire to be white with a red trace but the car has been around a long time, who can guess what has been done to it

Bill sdgpm

synchronicity again

Laurent, do as Bob advises
Bill sdgpm

So always in english in the text with south french accent. LOL

I have a brown wire from A to the fusebox. I will connect it to the brownblue wire from the light switch. So I will have a direct connexion between the light switch and the fuse box.

I have investigate a little bit more. (Please do not laught!).
the brown wire from A1 goes to the turn the key contactor. But it changes to red and then to yellow. The yellow is dubble, one for the turn the key and anorther yellow wich changes to brown and is plug to NOTHING!

I know, the car was imported from USA and is now in France. Perhaps Atlantic Ocean has got mysterious effect on the wireing.

So I wil connect the brown wire from the regulator to the fuseboxe.

If it does not work, I will plug the blue wire from S of the solenoïde to the fusebox too.

And Inch allah (the car is insure to 9600 euros against burning)

laurent
ld derancourt

where abouts in France do you Live Laurent?
It might be easier to come over for the weekend and sort it out for you? :-))
Robert (Bob) Midget Turbo

Bob,
I leave between Lyon and Saint etienne, so 900 km to reach Dover.
difficult for a weekend.
ld derancourt

So I have done the work like the drawing of Bill, and everythin works.
when engine turns at idle, I have a battery charge at 14,46V.
When I put the lignts, the indicator lamp and the wippers, the ammeter shows no discharge.
If I only put the heater motor, I have a discharge on the ammeter and the battery shows 14,39 V.
If I stop the heater motor, the ammeter returns to O and the battery immediatly returns to 14,46 V.
What does it mean?
laurent
ld derancourt

It means, Where have you got the ammeter plugged into?
Robert (Bob) Midget Turbo

If the ammeter is in the wiring at the proper place it would register all items that are switched on.

if it isnt it might only measure some item working, which yours seems to be doing.

A picture or a wiring drawing would help us work it out for you, your turn to draw one for us Laurent!

The alternator is doing its job properly anyway, 14.46v is fine. With an alternator I wouldnt even bother with an ammeter, the voltmeter will watch over the car enough for everyday running.
Bill sdgpm

please find enclosed a drawing


ld derancourt

Ld somewhere your diagram is wrong!!

Please disconnect the brown wire from the rear of the ammeter. (open circuit) and then tell me what works (marche), (wiper lights etc?)
Robert (Bob) Midget Turbo

Ld,
drop me an email si vous voulais, je suis proche,

Brad
Brad (Sprite IV 1380)

Brad, when I disconnect the brown wire from the anmeter, wippers work
but, horn, lights and heater do not work.
laurent
ld derancourt

This thread was discussed between 15/02/2009 and 22/02/2009

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