Headlight or indicators but not both

[keith55]

Just recommissioned my '77 Strada after importing from Germany.

She runs well but I have found that the indicators only work if the lights are off. When I turn the lights on, the indicators stop functioning. I'm wondering if I need to up the power of the battery.

The fitted battery is 12V 9A whilst the workshop manual indicates a 15 Amp battery is required.

I have also had fitted a Cibie headlamp unit.

Any thoughts gratefully received.

Thank you.

[danomar]

The first thing I would look at is the battery. One must install the correct 15amp one for everything to work properly. I learned this the hard way similar to you.

One easy thing to do: Replace the turn signal relay. They are inexpensive and should be easily obtained.

The only other thing I can think of is to check the headlamp. I believe the original bulb should be 45/55w, but someone else here will surely know the precise values. Suffice it to say that a higher-wattage bulb will suck too much electricity for the turn signals to work properly. This I also learned the hard way...

It might be worth checking all the ground connections and perhaps adding another frame ground point directly to the battery. I put one at the horn mount (headstock area) and then installed a relay to ensure the horn continues to work.

HTH
d

[MickeyMoto]

Assuming a 60/55 headlight, 21 watt indicators the load on full beam with idiot lights, tail light and instrument bulbs would be about 120 Watts or 10 amps. A fully charged 12 volt 9 amp hour battery will still run the load, but would discharge quicker than a 15 amp hour battery. If the engine is running with a 140 watt alternator at decent revs this will have more output than the load on the battery so enough to trickle charge the battery and run all the lights, although at low revs this would not be true. The indicators (with brake light on) are only used for short periods.

Is this with the engine running, or in the garage? Have you checked the alternator? Does the same thing happen whilst riding?

So, I would say you probably have either a duff battery (you did not say if it was new) or most probably an earthing problem. The larger batteries were fitted to electric start bikes and a 9amp hour is the correct battery for a non electric start bike, I think (I stand to be corrected).

I ran a 9 amp hour battery on a 501 with no electric start and a 60/55 watt headlight with no problems.

[robint]

Certainly ensure wiring connections and earths are good, the latter particularly! Also the original relays are essentially the bimetallic strip type where volts and heat do the switching and lack of sufficient volts and a recalcitrant strip(!) cause alll sorts of non flashing etc. Changing to an electronic LED flasher sends a regular pulsed spike at battery voltage to the switch and hence on to the bulbs so there is a consistent flash but of course still at whatever the battery voltage is at. Charging system however should be able to cope with the loads though as long as battery is accepting and holding charge.

[keith55]

Thank you gentlemen. Your advice appreciated,