Not Sure Which Subsystem To Troubleshoot

[BLAZY]

I'm running through my electrics before riding and I notice something odd. When the bike is idling, the turn signals blink at a steady rate. When I rev the bike, the signals (either side) start to flicker like there's a loose connection somewhere. Not blinking faster, but flickering intermittently. Return to idle, and they blink at the regular rate. I didn't notice the tail or headlight varying with the engine speed.

After a 10 minute break-in ride (neighborhood, up and down through the gears), when I hooked up the battery tender, the battery started charging like mad-I could hear it bubbling lightly. A 10 minute ride required nearly 20 minutes of charging before the tender cut back to the maintenance trickle. That tells me it had discharged more than I would have expected.

I have standard wattage bulbs in all the sockets, except I have LED peanut bulbs in the instrument light sockets.

The battery is less than a year old, and has been on a smart tender since I installed it. I've unplugged and replugged everything in the headlight shell and under the seats. The connectors are all clean and shiny.

Any suggestions where to start? I have a multimeter and time on my hands.

[Alan H]

LED bulb in the indicator tell tale?
Bin it for the correct one. Mixing bulbs is a recipe for problems.
You need a double tell tale bulb so it works both ways and I've never seen one yet.
Stop/tail OK, and if you put them in indicators, you need resistors or a new relay, so pointless.

Could be a possible duff battery cell to - try a known good battery and check earths.

[ConnerVT]

The mechanical flasher relay needs the proper load to operate correctly. Replace the flasher indicator bulb for the proper 1.7W bulb.

The erratic flashing could be one of two things:

1. The voltage in the turn signal circuit is high, and the load from the indicator bulb is too low for the flasher to work correctly; or
2. The voltage in the turn signal circuit is to low, and the voltage drops even lower when engine revs increase (ignition working harder).

The second may be likely, as you are also mentioning battery charge issues. Replacing the battery and troubleshooting your charging system are probably in your future.

[BLAZY]

I'll swap the indicator bulb and see if that cures the problem. I'll check the charging output, as well. Thanks.

[jabcb]

Which bike is this?
Is the electrical system stock except for the instrument bulbs?
What type of battery do you have?

Check the voltage at idle when the turn signals are ok & at revs when they are flickering.

Check the battery voltage after you charged it up & after its sat overnight without being on the charger.

[BLAZY]

76 GT500, stock electrical system, standard Yuasa lead/acid battery, on a Deltran Battery Tender since I installed it.

I'll check the voltage at the battery, static and running at 4000 rpm, per the manual. If it's bad, I'll test the regulator/rectifier.

I'll post the results. Thanks again!

[BLAZY]

Okay, a poor ground on the front turn signal stalks may have been the flickering, if it wasn't the LED indicator lamps. I swapped the LED peanut bulbs for the proper incandescent ones and added a washer under the turn signal stalk nut for a better connection. No more flickering at higher RPM.

Static battery voltage was 13.2 an hour after I disconnected the battery tender. At 4000 rpm, I had 13.7-13.8. Never got to 14. Weak, but at least I'm not overcharging.

Comments?

[ConnerVT]

Did you test it with both headlight on and off? The headlight switch connects in more alternator coils.

I agree, 13.8 VDC is low for 4000 RPM.

Could be a bad/weak cell in the battery, pulling things down. A good test is to take battery off bike, and put on float charger. Measure voltage three times: Right after disconnecting battery from a day on the charger, again one hour later, and again 24 hours later.

This is the test which MotoBatt had me do, when I fried my battery (my fault - improper wiring).

The first two measurements can give you an idea if it is charging fully, and how much resiliency/"headroom" the battery has. How fresh it is, it's ability to handle varying charging voltages. A "12V" battery should be around 12.5-13.0 an hour off the charger.

After 24 hours, the voltage should not have dropped more than a few 10ths of a volt. If it is closer to 1.0-1.5 VDC, then you have a cell that's gone bad. A bad cell will pull down the reading you get when measuring the charging voltage when the battery is installed on the bike.

[jabcb]

After you’ve confirmed that the battery looks good per ConnerVT’s test, hook the battery up & check the voltage. Then start the bike & find the rpm when the voltage starts to rise above that voltage.

[BLAZY]

I'll check the battery per below. The headlight switch on this model is fixed in the "On" position, per new (that year) DOT regulations. Thanks.