1970 S: problem with the rear brake electrical

Hi.
This friday i have had a trip of 200 km in the night with the light switch on.
The bike run great.
But when i braked softly with the rear brake lever was lower the light intensity of the headlight.
This not happened with the front brake.
But, that is the problem, when i braked strong and suddendly the bike switch off the front light and the engine for a while.
I know that the white wire of the rear brake, comes from the ignition switch and goes to front brake and to the black wire from Pazon I.E., but cannot catch and switch off of the power!!!!!!!
But this not happens with the light switch off.
What i must check?
Thank you.
Piero

pierodn said:

I know that the white wire of the rear brake, comes from the ignition switch and goes to front brake and to the black wire from Pazon I.E.,

Click to expand...

The white from the ignition switch should not be connected to the Pazon black (coil) wire.

Assuming standard positive earth/ground, white from the ignition switch should connect to the Pazon white.

http://www.pazon.com/files/PDF/PA2.pdf
p.7, Fig.1

If there is already a (white) wire going to the Pazon box white from the ignition switch then the second white should be disconnected from the black.

L.A.B. said:

pierodn said:

I know that the white wire of the rear brake, comes from the ignition switch and goes to front brake and to the black wire from Pazon I.E.,

Click to expand...

The white from the ignition switch should not be connected to the Pazon black (coil) wire.

Assuming standard positive earth/ground, white from the ignition switch should connect to the Pazon white.

http://www.pazon.com/files/PDF/PA2.pdf
p.7, Fig.1

If there is already a (white) wire going to the Pazon box white from the ignition switch then the second white should be disconnected from the black.

Click to expand...

Hi Les,
sorry, i meant that the white from Pazon ignition module keeps power joined to the white from ignition swithc.
This white from ignition switch goes already to the front and rear brake switch.
Thank you.
Piero

Sounds like there is a short circuit in the rear brake light that is dragging down the voltage only when the rear brake is used. Try removing the bulb and see if there is something wrong with the socket. Or the bulb itself is bad. Try again with no bulb.

Russ

Had a similar issue last week, operating either brake caused the engine to splutter and 10 secs later the main fuse to blow. Took all the brown wire connections off and this cured it but no brake light of course. Tested the resistance to earth on all the brown wire connections and it showed a route to earth which I found under the tank where the bullet had worked itself out enough to touch the head steady but still be in the connector, other places to check are the brown wire down by the rear brake light switch where it wears though and makes contact with the primary cover and at the rear light as it comes out of the mudguard.

Hi.
I will check.
Thank you.
Piero

Piero, remove or replace the the bulb and operate the brake and see if it still does it. In the past i have hunted for hours for a wiring fault, only to find it was a defective bulb all along :x

Cheers,

cliffa.

I've also had it where the wires grew slack, drooped down on to the exhaust pipe, then melt through the insulation.
easy enough to check.