Headlight and Instrument Lights

[Chris D]

Hello All, I have read your posts for quit a long time first time posting. I have a 1979 GS 1000 E it has a Vetter fairing on it. My question is while riding at night (oblivisously) my headlight and instruments will be bright and after a while they will go dim and then bright for awhile and then dim (you get the point). I am thinking that it is my R/R. The R/R is an aftermart one, that the previous owner must have replaced. Is my thought that the R/R is the problem? Or could it be something else? Thank you for your comments and thoughts.

Thank You,
Chris Dailey

[argonsagas]

Fluctuation in light output is a result of fluctuation in voltage, so you are probably right about the R/R. There is an "In the Garage" section on thie sit that will give you something called The Stator Papers. Print them out and use a good volt-ohmmeter to check your system.


Apart from the R/R the most likely problem is dirty/corroded connections or an intermittent short in your system. The short seems unlikely because you have no blown fuses.


Before doing anything else, check your battery voltages 4 times, first while running at idle, second at about 5000RPM, third about 15 minutes after shutdown, and the fourth after about 10 to 12 hours. Write down the numbers for accurate reference.

Do the battery check first so that you will know if any difference shows up when you do the next step, which is cleaning the fuse box and battery connections.

It is quite possible you have corroded and/or dirty connections, and the voltage is varying because of these, because there is always a voltage loss in getting through the dirt.

Before doing the stator checks or any repairs except the mentioned cleanup , give the battery a trickle charge overnight (amperage rate of 2 amps maximum, but preferably less).

[focus frenzy]

I agree, make sure and clean all the contacts and conections in the headlight circut including the fuse box contacts before proceding with the system test.
the vast majority of electrical problems you will come across with one of these bikes can be traced to bad conections.
suzuki used brass plated conectors and the tarnish that forms on brass is a very poor conductor.

[Chris D]

Thank you I will try your ideas.

Thank You,
Chris