Horn issues

The Commando horn is not fussy as to which way round you decide to wire it up.

The Commando horn can afford not to be fussy. No-one can get to it to teach it the error of its ways ! :-)

Graeme. Major tip, go to the RGM Norton  site and look at the workshop manuals page.

PART NO: 06514 could be the one that you require?

Hi Graeme. Andover Norton have the manual.

06.5146 WORKSHOP MANUAL 750/850 1970 - 1974

Note the year, perhaps this covers your model?

It has a number of wiring diagrams covering the Commando from pre 1971 to 1971/72/73.

Invaluable to anyone who wants to see the best results from their efforts.

Andover have their own numbering system similar to part numbers but they incorporate a full stop as above.

People say that the British invented bureaucracy, now it looks as if Austria is plagued with it to a greater degree.

Rgds.

Paul.

Dealing with the original problem. The horn is virtually inacessible, on the front bottom of the rear mudguard. The easy answer to is to fit a new item as and where you can. Wiring-IF it is ORIGINAL wiring then the two connectors seen above are NOT the ones. The RED is an earth and the BRN/BLU is battery live. The original horn wires are as follows-Is this a 750 with the 2 position ignition switch? If so the horn will be fed with a BRN/BLU and 'made noisy' by a BRN/BLK (earth) fed from the handlebar switch. IF this is an 850 with the 4 way ignition switch. Then the horn will have a RED earth and PPL/BLK (live) from the handlebar switch which in turn is fed with a WHT from the ignition switch.

Connect the side of a light bulb to the brown and blue wire and then touch the other bulb terminal onto the aluminium casing. The bulb should light as this wire is a permanent live.

Connect the side of a light bulb to the brown and blue wire and then touch the other bulb terminal onto the red wire then press the horn button the bulb should light. If not try pressing the bake lever as this wiring could be for the brake light switch.

If the light: doesn't light the switch is faulty; does light the horn is faulty. Let us know the outcome.

The attachment shows the basic wiring for a horn. Ignore the polarity and wiring colours it is from a book I wrote some years back.

On the LHS side of the frame on the Commando (750) is a two pin socket, (very often associated with 12V supplies inside caravans) Such a socket should have live (BRN/BLU) and and earth (RED) But the two wires on the Socket are very small ring terminals. The questioned connectors appear to be Luca. They are the correct colours for the 2MC but that has a smaller Luca on the earth, also the 2MC wires shouldn't be able to come that far down on the bike.