Fitting Halogen Headlamp

A question which may confirm my electrical incompetence.

I have just replaced the standard head lamp with a Halogen unit (made in Taiwan!) in my ’73 850 i/state after getting a stone through the original. The original had a single wire to the pilot light plus hi, lo and earth(?) from main. Earth off the main, with all the metal to metal contacts, presumeably also serviced the pilot bulb? The new has the pilot light in a rubber grommet so main and pilot each have their own earth wire – I have twinned these and joined to the original earth connection. Other three connections are as before.

With the key in the “lights on” position the pilot light comes on. When the headlamp switch is thrown the low beam comes on, the pilot light stays on (don’t know whether it should nor whether it was doing this before) and the green full beam indicator light comes on half bright (don’t remember this happening before). When the full beam switch is thrown - full beam comes on, pilot light still on and green light gets twice as bright.

From the Haynes manual the only change in wiring I can see within the shell is indicator wires swapped left for right, but my indicator switch is on throttle hand - opposite of original? – so ok?

Any comments on the wiring arrangement and on which lights should shine when would be appreciated.

Halogen headlight

The pilot is supposed to be on anytime the ignition switch is in the lighting position, so you're fine there. The only issue you have is the high beam indicator light half on when on the low beam. Check your ground wire to the indicator. If it's bad you could be getting a circuit through the high beam filament which is why it would be half bright (resistance).

Curious, is the headlight brighter now with the halogen. There's an article for BMWs telling how high resistance wiring (aka too small a diameter and corroded terminals) robs current going to the headlight and that a halogen under these conditions may not be any brighter or even less bright than the stock headlight. I know some of the local clubmen have increased wire diameter and added relays with very good results to headlight brightness.

Thanks David. good to know that some of it is working ok.

Have had a play - after disconnecting the earth from the pilot/hi/lo beams, with key on get a very dim pilot light and fairly bright green hi beam indicator after a short pause. Throw headlamp switch and pilot goes out and green gets slightly brighter. Sounds like a short somewhere?

With pilot/hi/lo earthed and fiddle with the various connectors, the green does go out occassionally - but too many wires in a small space - haven't worked out which one does it yet.

On your query, I hadn't ridden with the old light at night for some time (lights mainly used daytime to give the cars something to aim at), and not at all with the new one yet, but the high beam does seem much brighter with the halogen.

The blue/white wire from the hi-beam indicator (green light) should be connected via a double bullet connector to the blue/white feed from the hi/lo handle bar switch along with the hi beam feed wire from the bulb. The red wire from the indicator is earthed. With these connections the indicator cannot be illuminated except when current is supplied to the hi-beam filament.
Check for current at the blue/white feed from the handlebar switch when on lo-beam. If there is measurable current, dis-assemble the handlebar switch and check the contacts. These switches are known for corrosion. Usually cleaning will restore them.

Ron L.

Thanks Ron,

I now own a multimeter.

"The blue/white wire from the hi-beam indicator (green light) should be connected via a double bullet connector to the blue/white feed from the hi/lo handle bar switch along with the hi beam feed wire from the bulb. The red wire from the indicator is earthed." All wiring is as you list.

"With these connections the indicator cannot be illuminated except when current is supplied to the hi-beam filament. "

"Check for current at the blue/white feed from the handlebar switch when on lo-beam." If I unplug the headlight high beam lead from the double bullet connector I get 0V on Lo and 11.5V on Hi from the blue/white lead. With headlight high beam lead plugged in I get 5.5V on Lo and 9.5V on Hi from the blue/white. :?:

"If there is measurable current, dis-assemble the handlebar switch and check the contacts. These switches are known for corrosion. Usually cleaning will restore them." Have pulled this apart, was a bit mucky in there but contacts didn't look too bad, but have given all a tidy up. Still get the same results now all back together.

As you may guess I am still confused so any further suggestions will be gratefully recieved.

ntst8,

"If I unplug the headlight high beam lead from the double bullet connector I get 0V on Lo and 11.5V on Hi from the blue/white lead. With headlight high beam lead plugged in I get 5.5V on Lo and 9.5V on Hi from the blue/white. "

O.K. If you are getting current on the Hi-beam lead ONLY when the Hi-Beam lead is plugged into the connector with the warning light and Hi-Beam filament, then I would suspect that somehow you are getting current on your earth connection. Are both the warning light and high beam earthed through the headlight shell? Try taking a separate temporary earth from the cylinder head to both the warning light and the Hi-Beam headlight filament. If all works normally then you have a short somehow in the headlight bucket.

Hope this helps.

Ron L

ntst8,

Just re-read the opening message. Did you replace the headlight connector with the new headlight? If so check for an internal short in the connector. (Continuity between the Hi-beam lead and the earth lead).

Ron L

where do you guys get your halogen lights from? are they even remotely "period correct" looking?

does the entire unit get replaced or do you keep the housing but replace the internals?

yes, you guessed it.... went for a ride in the dark and realized i was glad i knew the roads :shock:

Halogen headlamps were fitted by Norton for some markets on the later bikes. I haven't seen the original type with the white Lucas logo for some years though.

The standard UK replacement is a Wipac- available from all the big dealers in L/H or R/H dip versions.

You would have to look very closely at the glass to see a difference.

The units fit straight into the original rims and shells but you will probably have to put a new connector on.

I have a Triumph Bonnie in my shed that has the original lucas Halogen light with the white lucas symbol on it. But the ones i have seen on Norvil look very much the same just no white lucas symbol.

As for original ~ after spending some 20 years in the Auto electrical trade.. I feel the original Lucas units were hardly the ultimate.

I chuckle when I see some of the BS prices asked on Ebay for original light units.

I paid $15 for a 7" headlight lens from an auto spares place and it was a sneeze to fit and it has the BEST light I have EVER had on any of my bikes and that includes one Hilda 750 CB !

The lens actually extends some 5-10mm beyond the chrome bezel and the overall lateral light spread is fantastic ~

And now I have fitted one of these new Xeon high output bulbs (that boast high out put and standard current consumption. And I reckon it is a fantastic unit.

Maybe it is Australia ~ as there is not a lot of concours events out here.. and besides there are LOT more roos and wallabies .. so in choosing between originality and practicality ` hmm~ hard call ! NOT!!! 8)

yes, i'd like the light beam to practically fry armadillos. much more important than originality, especially if it keeps you from dumping your "original" beauty b/c of road debris or other obstacles.