TR6P: two rectifiers

[TriNorBsa]

I'm just starting to look at the disaster that is the wiring on a 1972 (what started life as) TR6P. Most of the wires seem to be brown. Not a good start. However, there seems to be two 'modern' rectifiers, two alternator wires going to two terminals of one, and the other alternator wire going to a terminal of the other rectifier. Both rectifiers have an earth and both have a linked connection to the zener. I'm not sure at the moment which alternator wires are going to which rectifier (all brown remember, haven't worked back to the alternator yet to see where they originate), but the question is why would you have two rectifiers? Any ideas anyone?

[DM]

The two bridge rectifiers are being used to make up a 3 phase rectifier, two of the diodes in the second rectifier are redundant.

[TriNorBsa]

Okay thanks for the reply. I'm not too hot on what goes on in the detail of electrics - does this mean the alternator is different or is this just something you do?

[DM]

It will be a standard 3 phase alternator,  your two modern bridge rectifiers as wired work exactly the same as the original 3 phase rectifier.

[Rex]

- does this mean the alternator is different or is this just something you do?

Sadly it means Mr Make-do-and-mend has been at your bike . It's a worrying indicator of a reluctance to spend money on proper spares, especially as the correct three phase rect is hardly expensive in the context of reliable classic riding.

I would suggest springing for a combined reg+ rect unit (Pazon or Boyer) and a thorough check over of the rest of the bike and it's electrics.

[TriNorBsa]

The idea is to rewire using correct wire colours, as to the rest of the bike there's an abundance of home made brackets and, er, 'inspirational modifications' (read bodges). Despite this the bike was running remarkably well last time it was used except for rather excessive fuel consumption. But one thing at a time!