8 replies to this topic

[fpsasm]

Hello, I have a classic Mini MKi 1960, and i have upgraded to a alternator, i re-wired the car correctly according to various sources ( haynes, internet etc ).

After a few weeks, my alternator started producing 9.89 to 11.98 Volts..
To try to fix this problem, i have changed teh following: Regulator ; diode bridge ; brushes ; fuses .

Yet the voltage hasnt changed.

What solutions are there ?



by the way.. i have checked that the diodes are correctly working, regulator grounds correctly. and the between the diobes resistivity
i have also checked the: dashboard ; starter motor; fuses; distributer cap ; lights; and battery. for fault that could be causing the problem, but they all work correctly..

the car is negativily grounded

[taffy1967]

I think this is one for dklawson?

[Major Burkenshaw]

Have you checked the drive belt?

[fpsasm]

Have you checked the drive belt?

Yeap the drive belt is fine...

[fpsasm]

I also checked that connections are correct..

is it possible that my alternator is broke ful stops ?

[Major Burkenshaw]

Its possible that one of the windings have gone open circuit, can you see any physical damage to them? If you stip the alternator down you could test the continuity of the three windings where the connect to the rectifier.

Edited by Major Burkenshaw, 27 August 2008 - 08:37 AM.

[fpsasm]

Its possible that one of the windings have gone open circuit, can you see any physical damage to them? If you stip the alternator down you could test the continuity of the three windings where the connect to the rectifier.

yeah it looks like the windings are broken,

thanks for the help

[dklawson]

When it comes to testing an alternator, my advice is remove it from the car and take it to either a parts store or an electrical shop where it can be bench tested. The shop will tell you what's wrong and how much it will cost for repairs. On the other hand, the parts store will only tell you that the alternator is either good or bad and offer to sell you a new/rebuilt one if it's bad.

You said you followed the standard information in Haynes and elsewhere when you did the conversion. I wasn't aware that Haynes discussed this at all. When you replace the dynamo there are indeed several ways to convert the wiring but I'll summarize it succinctly below. See if this matches in practice what you achieved with your conversion.

At the old dynamo control box, remove the three heavy gauge wires and join them together.
Again at the control box, remove the two small gauge wires and join them. (Do not use the black earth wire).
Remove the dynamo and install the alternator.
Take the small dynamo wire and place it on the small alternator terminal.
Take the large dynamo wire and place it on one of the large alternator terminals.
If you want, run a second large wire from the remaining large alternator terminal to the battery side of the starter solenoid.
(You may have spliced the wires together to achieve this... or done the more cosmetic approach of modifying an old control box to act as a junction to connect the wires. The result is the same, it's just a matter of appearance.)

As has been discussed in several recent threads, the Lucas alternator requires that the charge light be working. You must observe the following:
Key off, engine off = warning light off
Key on, engine off = warning light on
Key on, engine on = warning light off

If you are seeing proper warning light operation and if in practice your wiring matches what I describe above, take the alternator to a shop for testing. Also keep in mind that batteries do not last forever. If your battery is more than three years old, consider it as another possible explanation for the problem.

[fpsasm]

You said you followed the standard information in Haynes and elsewhere when you did the conversion. I wasn't aware that Haynes discussed this at all. When you replace the dynamo there are indeed several ways to convert the wiring but I'll summarize it succinctly below. See if this matches in practice what you achieved with your conversion.

I worked of a circuit diagram in teh haynes manual which shows teh wiring for alternator..

Teh ign-light works just as u said..


thanks..