Morris Minor Owners Club

Well ! Bull Motif excelled themselves, REALLY helpfull on the phone RE the alternator and then sub 24 hour delivery on a standard ticket.

The alternator kit looks very good and brackets aren't precision but look well up to the task. The wiring loom is SUPERB authentic looking and well made. Assuming it's reliable (unlike some people here I've only ever had dynamo problems) it looks a really good deal.

According to my diagram page N44 in the BMC manual the Brown/Blue cable connected to A1 takes power from the +VE side of the battery (I'm thinking of the car as negative earth already) and supplies it to the regulator box and the ignition switch.

The Terminal next to it appears to supply power to the non ignition AUX equipment and the light's. This is terminal A.

What I would like to do is remove the regulator and fuse box (seen in fig N49) and replace them with a new durite fusebox with modern blade fuses.

This would also mean I could add fuses for items that don't have them now Fuelpump, lights and individual ones for the wipers etc also I could add extra's for the radio etc.

What worries me is that all the circuit diagrams I can see for the inside of the regulator have a coil of some description between A1 and A. Is this some kind of shunt to disconnect the lights when the starter is turning ? Should I be worried about defeating this? Should I fit a SPCO relay that lifts if the starter is operated ? Or a Zener ?

Any thoughts on this ?

Justin

From memory A supplies the non-switched accessories and A1 supplies the switched.

The 'shunt' you describe is nothing to do with disconnecting anything when the starter is operated and I begin to wonder why you thought this?? The SPCO relay and zener won't do much! (incidently what had you in mind for the Zener?? and what voltage would you select?? and why??). Not being funny, just wondered what you had in mind????

It's part of the internal voltage regulating mechanism. When disconnecting the regulator, (again from memory) you have to join A to A1 so that your accessories have power (I disconnected the regulator internals and just used the box as a junction box, but I joined A and A1 together).

Once you have done that and it's working then go to the fuse box and replace it with a more modern one (although you don't need to) and route your new separate wiring feeds to the appropriate places. It's a big job and your new loom will grow substantially!!

Cam wrote: The 'shunt' you describe is nothing to do with disconnecting anything when the starter is operated and I begin to wonder why you thought this?? The SPCO relay and zener won't do much! (incidently what had you in mind for the Zener?? and what voltage would you select?? and why??). Not being funny, just wondered what you had in mind????

Well I was guessing about ten volts for the Zener. What I thought happened(and I may be wrong that's why I asked) is that when the voltage dropped below ten volts or so then the power to the lights is cut in order to help the starter motor and ignition. The landrover for instance shorts the ballast resistor of the coil and kills the lights when you select the start position (ie turnover the starter).

I was assuming that this circuitry was something similar.

Are you sure it does that??

On virtually every other BL car (and I would suspect a lot of others) the ballast resistor is bypassed on starting to give the coil an extra boost. Normally a ballast coil is a 9v coil which receives 12v on starting then drops back to 9v (through the ballast) when it has started.

The Minor is too early for this system, but some later Minis had it.

It would be much easier to connect a SPCO relay to the starter position on the starter switch so the lights were killed whenever the starter solenoid had power (which is what I suspect your Landy does). Or simply don't start the car with the lights on as it's bad practice anyway.............

Cam wrote:Are you sure it does that??

No I thought it might:) hence the question Now I know it doesn't !

Thanks