Headlight no glo

[ME 109]

Patient: Sept 81 RS
D.O.B. (see above)
Colour: Remnant 507
Condition: used
Odometer: almost 250,000k


When I switch the headlight on, the high beam indicator comes on but no headlight, high or low.
The high beam indicator won't go out when switching from high to low beam.
The driving light operates with headlight switched on, but will not switch off with dip switch.
I haven't checked the headlight bulb yet because I'm pretty sure it did come on at one stage after this problem began.
Tail light and indicators work.
Relay for driving light under tank, switched from headlight high beam in bucket.
Headlight on/off switch located on fairing, overriding original un-switched headlight
Only thing to happen recently (that I'm aware of) is the right coil mount broke and the coil is now cable tied in position.


Am I being lazy by asking questions before pulling the rs apart?

[dougie]

Am I being lazy by asking questions before pulling the rs apart?

Yup - lazy.
(Why do you think I now have an "S" fairing? )

[Garnet]

I'd check for bullet holes.

Edit: Then look for a bad ground conection.

[ME 109]

I'll start the hunt after work today.

[Garnet]

I'll start the hunt after work today.

Start where all the brown wires are crimped to one connector, ususally at the coil. Give them all a good wiggle whilst watching the headlamp.

[ME 109]

Thanks Garnet, my rh coil bracket did break off a few weeks back. I'll start there.

[ME 109]

Couldn't find any earth problems external.
I did find that the headlight on/off switch wires going into the bucket (when wiggled) make the high beam indicator go off, and the headlight relay clicks..... but no light.
It may just be that the headlight bulb is blown which is making the high beam indicator come on, but I thought if that was the case, others would know.

I will tie a rope around my ankle with the other end tied to the front flake.
Then I'll go into the bucket. Right to the back if I have to.

[dougie]

It may just be an old wives tale, but I heard once, somewhere, that some lighting systems go to hi-beam when the lo-beam burns out. A kind of safety feature.

[ME 109]

I found it. It's roasted.

It could even be toasted, which would be worse.
The headlight socket/plug on the wiring loom is trash and the earth wire came adrift.
Slow roasted over 30 years is my choice over quick toasted.
Current gobe is a 55/60.
I have had higher wattage globes in there over the years.
I 'think' there was some deterioration of the socket/plug last time I looked.

Everything checks out ok. Even the light bulb works. (controlled tests in the garage)

Better find another socket.
At least one of the wires looks as though it's been hot near its terminal, maybe the wayward earth wire contacted +
It will be worth upgrading the headlight wiring.

[dougie]

Motobins #79892. Wiring loom to headlight 1981-85. (not cheap)