Headlight switch

[Fritzc]

Another shocking discovery!!! While riding after dark, cold and tired, which I rarely do, I had an experience with a pucker factor of 9.5.
Upon switching to high beam, my headlight went out completely for a full second. I stopped in a safe place and tried it several times and in some cases the light went out for up to five seconds before coming on! Needless to say I rode the rest of the way home on low beam. I was wondering if I should remove switch, get some of that electrical cleaner spray stuff and hose it down. Anyone?

 

[robsryder]

The least expensive alternative may prove adequate. I'd suggest that you go to a Radio Shack or auto parts store and purchase a spray can of Electrical Contact Cleaner. Liberally spray the switchgear while moving the switch to its various positions. (It might also be worthwhile to place a couple of old rags / towels, etc on any bodywork that drips might encounter. For what it's worth - I've personally not had a problem with Electrical Contact Cleaner affecting paint - but better safe than sorry).

After a few applications with the contact cleaner you should test your switch gear to see if the light shines continuously or has some intermittent operation. If the switch gear needs to be replaced you are only out the cost of the contact cleaner spray (in addition to the switchgear).

Although I have used WD-40 to accomplish the same function as Contact Cleaner, it is my understanding that WD-40 can attract grit & dust and over time act to decrease the reliability of the electrical circuit (i.e., things work worse, not better).

If you were riding an old Triumph (or other fine British vehicle) equipped with Lucas electrical gear, then I would say that everything is working normally. Way back when I had an old Triumph TR-4 car. The symptoms that you describe were a normal part of operation. I can still recall a friend screaming in terror as we headed towards a concrete rail bridge on a dark night and dark road when the lights went out. I just jiggled the switch and the lights came right back on. As I said, a normal thing with Lucas.

BMWs, on the other hand, should work a bit better.

If the problem isn't in the switchgear, then a useful task is to trace the electrical circuit inspecting for obvious shorts (i.e., worn insulation), broken wires (less obvious, but sharply kinked wires could be a clue), and poor connections (including grounds). Use of dielectric grease (from auto parts place) should be used on electrical connections. If there are obvious signs of corrosion (discolored with green oxides), then a bit of scotchbrite can help renew the contacts. The dielectric grease helps to reduce oxydation and corrosion, thereby making a more effective connection.

Good Luck!

 

[Fritzc]

Thanks!

The least expensive alternative may prove adequate. I'd suggest that you go to a Radio Shack or auto parts store and purchase a spray can of Electrical Contact Cleaner. <snip> The dielectric grease helps to reduce oxydation and corrosion, thereby making a more effective connection.Good Luck!

Thanks for the advice. I'm headed out to Radio Shack right now.

 

[jasontdi]

Hopefully you saw the Deoxit there and bought that instead. It works wonders on any electrical contact from RCA plugs to your cell phone battery.

 

[swilson143]

In addition to the switch contacts, could be a sticking relay.

 

[Fritzc]

Thanks for the help, all!

Went to NAPA store and bought some QD electronic cleaner (CRC brand) sprayed out the innards of the switch and it seems to work fine now. I can switch from high beam to low beam again and again and again! It responds instantly now.

 

[jingdog]

Yeah had the same thing happen and fixed it with contact cleaner. Look out because in a few weeks the lights will go out when you use the switch again! You really need a new switch but if youre cheap like me...

 

[ANDYVH]

Another maintenance item on lighting that many riders are not aware of is the buildup of corrosion on the negative terminal of the headlight bulb connector. On my 94 RS it uses a H4 connector (3-prong terminal). For a while I was having repeated failures of the high beam of the aftermarket bulbs I was using. I mean, I had replaced three H4 bulbs in maybe 2 years (all different bulb brands). A friend of mine said to clean the bulb connections, especially the negative terminal. I did just that. So far, that was five years ago and I have not had a single bulb failure.

Just because you don't see corrosion doesn't mean it is not there. The corrosion raises the resistance in the circuit and makes the bulb less efficient.